RFR: 8313651: Add 'final' keyword to public property methods in controls [v3]

[Andy Goryachev]

> In the Control hierarchy, all property accessor methods must be declared `final`.
> 
> Added a test to check for missing `final` keyword and added the said keyword where required.

Andy Goryachev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - review comments
 - Merge remote-tracking branch 'origin/master' into 8313651.final
 - review comments
 - whitespace
 - added final keyword
 - test

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1213/files
  - new: https://git.openjdk.org/jfx/pull/1213/files/c7808a9f..797285d8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1213&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1213&range=01-02

  Stats: 188 lines in 10 files changed: 133 ins; 17 del; 38 mod
  Patch: https://git.openjdk.org/jfx/pull/1213.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1213/head:pull/1213

PR: https://git.openjdk.org/jfx/pull/1213