feature request: Enabling typescript isolated modules

[SimonSiefke]

Related #160416

For migrating towards ESM in VSCode, it seems the tsconfig isolatedModules option could be useful, ensuring that imports are compatible with ESM.

For example, this typescript code transpiled to javascript would cause a runtime error because of the someType export:

import { someType, someFunction } from "someModule";
 
someFunction();

export { someType, someFunction };

The isolatedModules rule would enforce a type only import for someType:

import { type someType, someFunction } from "someModule";
 
someFunction();

export { type someType, someFunction };

Enabling the isolatedModules tsconfig option in VSCode, it seems these files would need to adjusted:

Found 26 errors in 6 files.

Errors  Files
     9  src/vs/base/common/amd.ts:57
     4  src/vs/base/node/processes.ts:14
     1  src/vs/workbench/contrib/accessibility/browser/accessibilityConfiguration.ts:636
     1  src/vs/workbench/contrib/inlineChat/common/inlineChat.ts:172
     8  src/vs/workbench/contrib/performance/browser/perfviewEditor.ts:331
     3  src/vs/workbench/contrib/tasks/common/taskService.ts:18

[jrieken]

We reverted this because we learnt, albeit very late, that it has disabled inlining of const enums. See #227372