fix(amazonq): avoid ERR_UNSUPPORTED_ESM_URL_SCHEME error when loading indexer on Windows (#1135)

## Problem

The codewhisperer server fails to load the project context indexer on windows, raising a `ERR_UNSUPPORTED_ESM_URL_SCHEME ` failure. This happens when the library is imported with a regular path on Windows:

https://github.com/aws/language-servers/blob/e4d4ef026c8a60cc1ddf08c981340a902d628016/server/aws-lsp-codewhisperer/src/shared/localProjectContextController.ts#L142-L143

Some information from nodejs/node#31710 indicates that code running on Windows must use URLs so that local file paths (including drive letters) are not mistakenly interpreted as things like http urls.

## Solution

Wrap the path in a URL when running on Windows.

Author: awschristou

server/aws-lsp-codewhisperer/src/shared/localProjectContextController.ts

@@ -20,6 +20,7 @@ import * as path from 'path'
 
 import * as ignore from 'ignore'
 import { fdir } from 'fdir'
+import { pathToFileURL } from 'url'
 
 const LIBRARY_DIR = (() => {
     if (require.main?.filename) {
@@ -139,7 +140,7 @@ export class LocalProjectContextController {
                     `index worker thread count: ${indexWorkerThreads}`
             )
 
-            const libraryPath = path.join(LIBRARY_DIR, 'dist', 'extension.js')
+            const libraryPath = this.getVectorLibraryPath()
             const vecLib = vectorLib ?? (await eval(`import("${libraryPath}")`))
             if (vecLib) {
                 this._vecLib = await vecLib.start(LIBRARY_DIR, this.clientName, this.indexCacheDirPath)
@@ -153,6 +154,19 @@ export class LocalProjectContextController {
         }
     }
 
+    private getVectorLibraryPath(): string {
+        const libraryPath = path.join(LIBRARY_DIR, 'dist', 'extension.js')
+
+        if (process.platform === 'win32') {
+            // On Windows, the path must be loaded using a URL.
+            // Using the file path directly results in ERR_UNSUPPORTED_ESM_URL_SCHEME
+            // More details: https://github.com/nodejs/node/issues/31710
+            return pathToFileURL(libraryPath).toString()
+        }
+
+        return libraryPath
+    }
+
     public async dispose(): Promise<void> {
         if (this._vecLib) {
             await this._vecLib?.clear?.()