Language service uses a canonical "Tour of Heroes" project to test
various features, but the files are all contained in test_data.ts which
is hard to read and often contains errors that are difficult to catch
without proper IDE syntax highlighting. The directory structure is also
not clear from first glance.
This PR refactors the test project into standalone files in the proper
format.
Next up:
[ ] Update the interface of MockTypeScript to only accept scriptNames.
[ ] Remove test_data.ts
PR Close#32653
Keen Yee Liau