feat(admin-bundler,admin-vite-plugin,medusa): Add support for loading Admin Extensions from plugins (#10869)

Should not be merged before https://github.com/medusajs/medusa/pull/10895

**What**
- Introduces a new `plugin` command to `admin-bundler`, currently not used anywhere but will be called from `medusa build:plugin`
- Discovers plugins with extensions and add passes the to `admin-vite-plugin`.
- Updates `admin-vite-plugin` so its able to read built admin extensions.

Resolves CMRC-830, CMRC-839

packages/admin/admin-vite-plugin/src/babel.ts

@@ -17,11 +17,13 @@ import {
   isTemplateLiteral,
   isVariableDeclaration,
   isVariableDeclarator,
+  Node,
   ObjectExpression,
   ObjectMethod,
   ObjectProperty,
   SpreadElement,
   StringLiteral,
+  VariableDeclarator,
 } from "@babel/types"
 
 /**
@@ -58,6 +60,7 @@ export type {
   ExportDefaultDeclaration,
   ExportNamedDeclaration,
   File,
+  Node,
   NodePath,
   ObjectExpression,
   ObjectMethod,
@@ -66,4 +69,5 @@ export type {
   ParserOptions,
   SpreadElement,
   StringLiteral,
+  VariableDeclarator,
 }