refactor: move @babel/helper-hoist-variables to ts

[JLHwung]

Q	A
Any Dependency Changes?	@babel/helper-hoist-variables now depends on @babel/traverse, from which it imports NodePath type.
License	MIT

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[nicolo-ribaudo]

I really dislike this, but this helper is used only by plugins so there is already a @babel/traverse dependency somewhere.

I wish yarn/npm supported typeDependencies, only downloaded for TS users.

[JLHwung]

We can re-export types exports of @babel/traverse in @babel/core or @babel/types. I think NodePath is the only heavily used type in @babel/traverse.

[existentialism]

+1 in @babel/types

[nicolo-ribaudo]

Let's re-export this from @babel/core, since it already depends on @babel/traverse (@babel/types doesn't).

I'll add a TODO so that we don't forget to update it after converting @babel/core.

[JLHwung]

Converted to draft since type checking it depends on transition of @babel/traverse to be done.

[nicolo-ribaudo]

@JLHwung @babel/traverse has been merged!