RFR: 8364560: The default value of --linux-menu-group option is invalid

[Alexey Semenyuk]

- Set the default value of the "Categories" key in .desktop files to "Utility".
  - The value of the "Categories" key is an ID, not a localizable string. This is why the "param.menu-group.default" localization key was removed.
- Add a test for the "--linux-menu-group" option.

-------------

Commit messages:
 - 8364560: The default value of --linux-menu-group option is invalid

Changes: https://git.openjdk.org/jdk/pull/28298/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28298&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364560
  Stats: 45 lines in 5 files changed: 33 ins; 4 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/28298.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28298/head:pull/28298

PR: https://git.openjdk.org/jdk/pull/28298