* Reduce extra output in compilation and tests
I couldn't stand the amount of extra output that we got when compiling
a clean project and when executing regular tests. We should strive to
keep output clean and not print anything additional to stdout/stderr.
* Getting rid of explicit setup by service loading
In order for SL4J to use service loading correctly had to upgrade to
latest slf4j. Unfortunately `TestLogProvider` which essentially
delegates to `logback` provider will lead to spurious ambiguous warnings
on multiple providers. In order to dictate which one to use and
therefore eliminate the warnings we can use the `slf4j.provider` env
var, which is only available in slf4j 2.x.
Now, there is no need to explicitly call `LoggerSetup.get().setup()` as
that is being called during service setup.
* legal review
* linter
* Ensure ConsoleHandler uses the default level
ConsoleHandler's constructor uses `Level.INFO` which is unnecessary for
tests.
* report warnings
Implement new Enso documentation parser; remove old Scala Enso parser.
Performance: Total time parsing documentation is now ~2ms.
# Important Notes
- Doc parsing is now done only in the frontend.
- Some engine tests had never been switched to the new parser. We should investigate tests that don't pass after the switch: #5894.
- The option to run the old searcher has been removed, as it is obsolete and was already broken before this (see #5909).
- Some interfaces used only by the old searcher have been removed.
