This PR migrates most remaining tests to the new test suite. It also
completes the migration of directories like `tests/lean/run`, meaning
that PRs trying to add tests to those old directories will now fail.
This PR fixes a bug where the unknown identifier code actions were
broken in NeoVim due to the language server not properly setting the
`data?` field for all code action items that it yields.
This PR fixes a bug in the unknown identifier code actions where the
identifiers wouldn't be correctly minimized in nested namespaces. It
also fixes a bug where identifiers would sometimes be minimized to
`[anonymous]`.
The first bug was introduced in #10619.
This PR significantly improves the test coverage of the language server,
providing at least a single basic test for every request that is used by
the client. It also implements infrastructure for testing all of these
requests, e.g. the ability to run interactive tests in a project context
and refactors the interactive test runner to be more maintainable.
Finally, it also fixes a small bug with the recently implemented unknown
identifier code actions for auto-implicits (#10442) that was discovered
in testing, where the "import all unambiguous unknown identifiers" code
action didn't work correctly on auto-implicit identifiers.
