Languages Sprint 154

[tsmaeder]

This sprint is dedicated to getting the jdt.ls branch ready to be merged. The tasks here are:

1. Fix selenium tests.
   The goal is to have an explanation for all failures that are not present in master, as well. As of last night, we have 123/654 failures, whereas master at 12/635. Errors that can be fixed easily or that are blockers to merging should be fixed, for all others, we need to make an issue.
2. Have jdt.ls branch reviewed and follow up on comments on the branch.
   Trivial changes should be done right away, for all others, we need an issue.
3. Manual testing.
   We should go through some real world scenarios to manually test Java support. We should do both scenario and component testing.
4. Verify che-in-che is still feasible.
   We haven't tested che-in-ch in a long time. Let's give it a go, once again.
5. Rebase once a week to reduce false changes. Due to removal of eclipse stuff, we have around 3500 changes, mostly removals

Related issues

Clean Up Java/Maven Leftovers #10872
Address Selenium Test Merge Blockers #9591
Review Callers of org.eclipse.jdt.ls.core.internal.JDTUtils.toLocation(IJavaElement) #10874
Allow to pass in jdt.ls Memory limit as a ENV variable #11044
Use notifications instead of client commands #11053
Udpate jdt.ls-specific stuff to EPL 2.0 #10595