Fix up import paths and groups in new TypeScript code.
Review Request #13171 — Created Aug. 1, 2023 and submitted — Latest diff uploaded
As we've defined how our JS codebase is going to work going forward,
we've not been terribly disciplined about how we do imports. This change
makes everything consistent with three import groups (3rd party, other
modules, and the current module) that kind of matches the way that our
Python code works. Where we can, this has been simplified to import
everything from the top-level indexes, which makes sorting things
alphabetically by module name much easier.
Ran js-tests.