RFR: 8338103: Stabilize and open source a Swing OGL ButtonResizeTest [v7]

[Manukumar V S]

> This PR creates a new test by stabilising and open sourcing a closed test.
> This test verifies that the OpenGL pipeline does not create artifacts with swing components after window is zoomed to maximum size and then resized back to normal.
> This test is run twice, with and without the flags "-Dsun.java2d.opengl=True -Dsun.java2d.opengl.fbobject=false" .
> 
> This is tested(15 times per platform) in all the available mach5 headful platforms and found to be stable.

Manukumar V S has updated the pull request incrementally with one additional commit since the last revision:

  Review comments fixed : Sorted imports, formatting changes, saving images only on failure, compare changed, dispose on EDT

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20532/files
  - new: https://git.openjdk.org/jdk/pull/20532/files/5694b681..715ddbc0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20532&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20532&range=05-06

  Stats: 45 lines in 1 file changed: 14 ins; 21 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/20532.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20532/head:pull/20532

PR: https://git.openjdk.org/jdk/pull/20532