Enable TS 4.2 features

[mjbvz]

Tracks support for TypeScript 4.2 features. We will not ship TS 4.2 this iteration since stable 4.2 will only be released in February. To preview these features, use the TypeScript and JavaScript Nightly extension with VS Code 1.53+

Sub Features:

• Find references to file: Context menu 'Find all references' on files from file explorer. #66150
• Semantic highlighting in TS Server: Difference in behavior with encodedSemanticClassifications-full in TS 4.1 compared to using VS Code plugin TypeScript#41262
• Hierarchical refactoring support in TS server: TSServer: Refactor trigger reason TypeScript#35096