Allow negative number in ambient const initializer

[JLHwung]

Q	A
Fixed Issues?	Fixes #15337
Patch: Bug Fix?	Yes
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR Link
Any Dependency Changes?
License	MIT

• Allow negative numbers in ambient const initializers. E.g.

declare module N {
  const negative_number = -1;
}

• Added new tests as it seems that the error is not covered by any other tests.

The literal AST difference between Babel and ESTree is somehow annoying, an estree boolean toggle is added so we don't have to take care of the inheritance ordering between the estree plugin and the typescript plugin. (We may want to enforce plugin orderings for estree and other language extensions.)

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/53762/