feat: add new parser babel-ts to parse TypeScript syntaxes via Babel

[JounQin]

• I’ve added tests to confirm my change works.
• (If changing the API or CLI) I’ve documented the changes I’ve made (in the docs/ directory)
• (If the change is user-facing) I’ve added my changes to the CHANGELOG.unreleased.md file following the template.
• I’ve read the contributing guidelines.

✨Try the playground for this PR✨

Motivation: Babel itself is able to parse TypeScript, but we haven't enabled it, which makes something like babel-preset-proposal-typescript can not integrate with Prettier perfectly, but it should be easy to support it.

[j-f1]

Can you add some more thorough tests (i.e. by adding the babel-ts parser to a few existing TypeScript test cases) to make sure that the printer can handle the Babel-TypeScript AST just as well as the ESTree-Typescript AST?

[JounQin]

Can you add some more thorough tests (i.e. by adding the babel-ts parser to a few existing TypeScript test cases) to make sure that the printer can handle the Babel-TypeScript AST just as well as the ESTree-Typescript AST?

Done.

[alexander-akait]

Not sure we need 2 parsers for typescript

[JounQin]

Not sure we need 2 parsers for typescript

@evilebottnawi With babel-ts we will be able to integrate something like babel-preset-proposal-typescript as like in my PR description.

And we do have two parsers for flow. :)

[alexander-akait]

@JounQin 👍

[JounQin]

@duailibe Can you approve this PR? So that we merge it...

[duailibe]

@JounQin I'm aware. I still disagree with the combinations, there are still too many

I'm trying to fix it myself, and I'll update the PR today

[thorn0]

Tested --parser babel-ts on the following repos: Microsoft/TypeScript, ReactiveX/rxjs, and angular/angular. The results are identical to formatting with --parser typescript. Does anyone want to help with this and test it on some big TypeScript codebases? Remember that it can be installed directly from GitHub with yarn add JounQin/prettier#feat/babel_ts.

[alexander-akait]

@thorn0 I think we if we find some problems we can send a PR with fix, it is not easy to find all edge cases

[alexander-akait]

I think we can merge ⭐