[microsoft/TypeScript] allow voluntary .ts suffix for import paths (#37582)

## Search Terms .ts suffix imports ## Suggestion Typescript doesn't recognize file imports with ```.ts``` suffix. Allow voluntary ```.ts``` to be added to import paths. ## Use Cases It seems right to be able to use a correct path to a file without magic resolution. This would help to align with [deno](https://deno.land) which uses mandatory suffixes o files. ## Examples let ```import a from "path/to/a.ts"``` behave the same as ```import a from "path/to/a"``` ## Checklist My suggestion meets these guidelines: * [x] This wouldn't be a breaking change in existing TypeScript/JavaScript code * [x] This wouldn't change the runtime behavior of existing JavaScript code * [x] This could be implemented without emitting different JS based on the types of the expressions * [ ] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.) * [x] This feature would agree with the rest of [TypeScript's Design Goals](https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals).

Related Topics: TypeScript