vfs: lazy-load esm/formats to fix shared library builds

The eager require of 'internal/modules/esm/formats' at module
load time causes a TypeError in shared library builds where the
module is not available. Make the require lazy since it's only
needed when determining module format from file extension.

Author: mcollina

lib/internal/vfs/module_hooks.js

@@ -14,7 +14,7 @@ const {
 const path = require('path');
 const { dirname, extname, isAbsolute, resolve } = path;
 const pathPosix = path.posix;
-const { extensionFormatMap } = require('internal/modules/esm/formats');
+let extensionFormatMap;
 
 /**
  * Normalizes a VFS path. Uses POSIX normalization for Unix-style paths (starting with /)
@@ -396,6 +396,9 @@ function getFormatFromExtension(filePath) {
     if (type === 'module') return 'module';
     return 'commonjs';
   }
+  if (extensionFormatMap === undefined) {
+    extensionFormatMap = require('internal/modules/esm/formats').extensionFormatMap;
+  }
   return extensionFormatMap[ext] ?? 'commonjs';
 }