RFR: 8344063: Remove doPrivileged calls from swing classes in the java.desktop module

[Phil Race]

This is the first of a number of PRs to remove doPrivileged uses in client libraries.
These calls are obsolete dead code after JEP 486.

I have run all our automated tests, including JCK tests, and manually tested SwingSet.

One thing I might have missed in a couple of cases is that it seems that javac doesn't seem to notice if you leave an un-needed SuppressWarnings("removal") annotation. 

As per the bug report I am limiting (as much as I can) what I touch here to be just the immediate consequences of removing doPrivileged calls. These changes are plenty enough as it is.

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

Commit messages:
 - 8344063
 - 8344063

Changes: https://git.openjdk.org/jdk/pull/22090/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22090&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344063
  Stats: 573 lines in 28 files changed: 55 ins; 366 del; 152 mod
  Patch: https://git.openjdk.org/jdk/pull/22090.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22090/head:pull/22090

PR: https://git.openjdk.org/jdk/pull/22090