[#1336] Prepare for 3.0.0 release

[eparovyshnaya]

• update version for pom.xml manifests
• update version for MANIFEST.MF manifests
• update version for feature.xml manifests
• update version for product manifests
• update version for p2.inf manifests
• update version for public keys
• update about.properties
• update bundle.properties
• update plugin.properties
• update feature.properties

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 33.71%. Comparing base (d8a2dab) to head (c059f73). Report is 6 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1338 +/- ## ============================================ - Coverage 33.73% 33.71% -0.02% Complexity 394 394 ============================================ Files 1190 1190 Lines 25996 25996 Branches 1595 1595 ============================================ - Hits 8770 8765 -5 - Misses 16701 16707 +6 + Partials 525 524 -1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.