RFR: 8307538: Memory leak in TreeTableView when calling refresh [v2]

[Andy Goryachev]

> Fixed a memory leak in TreeTableView by using WeakInvalidationListener (which is the right approach in this particular situation) - the leak is specific to TreeTableRowSkin.
> 
> Added a unit test.
> 
> Added Refresh buttons and Skin menu to the Monkey Tester (will expand these to other controls as a part next MT update).

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 10 additional commits since the last revision:

 - removed monkey tester changes
 - Merge remote-tracking branch 'origin/master' into 8307538.refresh
 - whitespace
 - updated test
 - variable tree cell fix
 - fixed size selector
 - list view page
 - fix and test
 - skin menu
 - refresh button

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1129/files
  - new: https://git.openjdk.org/jfx/pull/1129/files/cc2f42e8..2b1ae8b7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1129&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1129&range=00-01

  Stats: 459 lines in 20 files changed: 131 ins; 270 del; 58 mod
  Patch: https://git.openjdk.org/jfx/pull/1129.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1129/head:pull/1129

PR: https://git.openjdk.org/jfx/pull/1129