breaking: Standalone builds (#9496)

Fixes: FRMW-2742

In this PR, we fix the build output of the backend source code, which eliminates a lot of magic between the development and production environments.

Right now, we only compile the source files from the `src` directory and write them within the `dist` directory.

**Here's how the `src` directory with a custom module looks like**

```
src
├── modules
│   └── hello
│       ├── index.ts
```

**Here's the build output**

```
dist
├── modules
│   └── hello
│       ├── index.js
```

Let's imagine a file at the root of your project (maybe the `medusa-config.js` file) that wants to import the `modules/hello/index` file. How can we ensure that the import will work in both the development and production environments?

If we write the import targeting the `src` directory, it will break in production because it should target the `dist` directory.

## Solution
The solution is to compile everything within the project and mimic the file structure in the build output, not just the `src` directory.

**Here's how the fixed output should look like**

```
dist
├── src
│  ├── modules
│  │   └── hello
│  │       ├── index.js
├── medusa-config.js
├── yarn.lock
├── package.json
```

If you notice carefully, we also have `medusa-config.js`, `yarn.lock`, and `package.json` within the `dist` directory. We do so to create a standalone built application, something you can copy/paste to your server and run without relying on the original source code.

- This results in small containers since you are not copying unnecessary files.
- Clear distinction between the development and the production code. If you want to run the production server, then `cd` into the `dist` directory and run it from there.

## Changes in the PR

- Breaking: Remove the `dist` and `build` folders. Instead, write them production artefacts within the `.medusa` directory as `.medusa/admin` and `.medusa/server`.
- Breaking: Change the output of the `.medusa/server` folder to mimic the root project structure.
- Refactor: Remove `Symbol.for("ts-node.register.instance")]` check to find from where to load the source code.
- Refactor: Use `tsc` for creating the production build. This ensures we respect `tsconfig` settings when creating the build and also perform type-checking.

Co-authored-by: Adrien de Peretti <25098370+adrien2p@users.noreply.github.com>

packages/core/modules-sdk/src/loaders/__fixtures__/test-service-resolved/index.ts

@@ -0,0 +1 @@
+export default {}

packages/core/modules-sdk/src/loaders/__fixtures__/test-service/index.ts

@@ -0,0 +1 @@
+export default {}

packages/core/modules-sdk/src/loaders/__tests__/register-modules.ts

@@ -3,13 +3,15 @@ import { ModulesDefinition } from "../../definitions"
 import { MODULE_RESOURCE_TYPE, MODULE_SCOPE } from "../../types"
 import { registerMedusaModule } from "../register-modules"
 
-const RESOLVED_PACKAGE = "@medusajs/test-service-resolved"
-jest.mock("resolve-cwd", () => jest.fn(() => RESOLVED_PACKAGE))
+const testServiceResolved = require.resolve(
+  "../__fixtures__/test-service-resolved"
+)
+const defaultTestService = require.resolve("../__fixtures__/test-service")
 
 describe("module definitions loader", () => {
   const defaultDefinition: ModuleDefinition = {
     key: "testService",
-    defaultPackage: "@medusajs/test-service",
+    defaultPackage: defaultTestService,
     label: "TestService",
     isRequired: false,
     defaultModuleDeclaration: {
@@ -51,6 +53,7 @@ describe("module definitions loader", () => {
 
   it("Resolves a custom module without pre-defined definition", () => {
     const res = registerMedusaModule("customModulesABC", {
+      resolve: testServiceResolved,
       options: {
         test: 123,
       },
@@ -58,7 +61,7 @@ describe("module definitions loader", () => {
 
     expect(res).toEqual({
       customModulesABC: expect.objectContaining({
-        resolutionPath: "@medusajs/test-service-resolved",
+        resolutionPath: testServiceResolved,
         definition: expect.objectContaining({
           key: "customModulesABC",
           label: "Custom: customModulesABC",
@@ -146,7 +149,7 @@ describe("module definitions loader", () => {
 
       expect(res[defaultDefinition.key]).toEqual(
         expect.objectContaining({
-          resolutionPath: RESOLVED_PACKAGE,
+          resolutionPath: defaultTestService,
           definition: defaultDefinition,
           options: {},
           moduleDeclaration: {
@@ -172,7 +175,7 @@ describe("module definitions loader", () => {
 
       expect(res[defaultDefinition.key]).toEqual(
         expect.objectContaining({
-          resolutionPath: RESOLVED_PACKAGE,
+          resolutionPath: defaultTestService,
           definition: defaultDefinition,
           options: {},
           moduleDeclaration: {
@@ -221,7 +224,7 @@ describe("module definitions loader", () => {
 
       expect(res[defaultDefinition.key]).toEqual(
         expect.objectContaining({
-          resolutionPath: RESOLVED_PACKAGE,
+          resolutionPath: defaultTestService,
           definition: defaultDefinition,
           options: { test: 123 },
           moduleDeclaration: {

packages/core/modules-sdk/src/loaders/register-modules.ts

@@ -11,7 +11,6 @@ import {
   isString,
   normalizeImportPathWithSource,
 } from "@medusajs/utils"
-import resolveCwd from "resolve-cwd"
 import { ModulesDefinition } from "../definitions"
 import { MODULE_RESOURCE_TYPE, MODULE_SCOPE } from "../types"
 
@@ -68,7 +67,7 @@ function getCustomModuleResolution(
   const originalPath = normalizeImportPathWithSource(
     (isString(moduleConfig) ? moduleConfig : moduleConfig.resolve) as string
   )
-  const resolutionPath = resolveCwd(originalPath)
+  const resolutionPath = require.resolve(originalPath)
 
   const conf = isObject(moduleConfig)
     ? moduleConfig
@@ -143,7 +142,7 @@ function getInternalModuleResolution(
     const originalPath = normalizeImportPathWithSource(
       (isString(moduleConfig) ? moduleConfig : moduleConfig.resolve) as string
     )
-    resolutionPath = resolveCwd(originalPath)
+    resolutionPath = require.resolve(originalPath)
   }
 
   const moduleDeclaration = isObj ? moduleConfig : {}