fix(medusa-dev): include packages/ subdirectories in discovery (#3293)

## What

Include packages/ subdirectories in medusa-dev packages discovery.

## Why

We started to use subdirectories in the monorepo `packages/` directory in order to better organize packages.

Packages in subdirectories were invisible to `medusa-dev` and could not be copied.

## How

Rely on monorepo package.json workspace glob patterns to discover packages that can be published to the local npm registry.

packages/medusa-dev-cli/src/local-npm-registry/install-packages.js

@@ -24,9 +24,16 @@ const installPackages = async ({
     // in workspaces which should preserve node_modules structure
     // (packages being mostly hoisted to top-level node_modules)
 
+    const { stdout: yarnVersion } = await promisifiedSpawn([
+      `yarn`,
+      [`--version`],
+      { stdio: `pipe` },
+    ])
+    const workspaceCommand = !yarnVersion.startsWith("1") ? "list" : "info"
+
     const { stdout } = await promisifiedSpawn([
       `yarn`,
-      [`workspaces`, `info`, `--json`],
+      [`workspaces`, workspaceCommand, `--json`],
       { stdio: `pipe` },
     ])