NPE
Merge remote-tracking branch 'origin/master'
platform: update check and notifications reworked

- home directory accessibility check for patch upgrades (IDEA-90067)
- update result dialogs and notifications fixed
- text messages moved to bundle
- code duplication reduced
- check intervals fixed
- time of last check notification fixed
- version formatting (IDEA-118261)
- check time reduced (no plugin check if platform update is available)
Cleanup (deprecation; dead code)