RFR: 8301312: Create implementation of NSAccessibilityButton protocol [v7]

[Alexander Zuev]

> Add the common base component for all the new implementing native classes Change native peer creation to use the new base component The new code will instantiate new protocol implementation  for the given role if it exists or an old one if it does not exist
> Added BUTTON role implementing class

Alexander Zuev has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 11 commits:

 - Merge branch 'master' into JDK-8301312
 - Changing performAction parameter to NSString
 - Merge remote-tracking branch 'refs/remotes/origin/JDK-8301312' into JDK-8301312
 - Properly use NSObject instead of the GlassAccessible type.
 - Fixed situation when performAction throws an exception on Java side - now we are properly
   returning FALSE notifying system that action has not been performed successfully.
 - Fixes based on review.
   Modified parent retrieval to cache the parent inside the component peer because retrieving parent every time
   can be costly.
 - 8301312: Create implementation of NSAccessibilityButton protocol
   
   Add the common base component for all the new implementing native classes
   Change native peer creation to use the new base component
   The new code will instantiate new protocol implementation  for the given role
   if it exists or an old one if it does not exist
   Added BUTTON role implementing class
 - Properly use NSObject instead of the GlassAccessible type.
 - Fixed situation when performAction throws an exception on Java side - now we are properly
   returning FALSE notifying system that action has not been performed successfully.
 - Fixes based on review.
   Modified parent retrieval to cache the parent inside the component peer because retrieving parent every time
   can be costly.
 - ... and 1 more: https://git.openjdk.org/jfx/compare/f8c8a8a1...871a2ad5

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

Changes: https://git.openjdk.org/jfx/pull/1084/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1084&range=06
  Stats: 421 lines in 7 files changed: 372 ins; 41 del; 8 mod
  Patch: https://git.openjdk.org/jfx/pull/1084.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1084/head:pull/1084

PR: https://git.openjdk.org/jfx/pull/1084