RFR: 8328716: [TestBug] Screen capturing utility for failed tests [v4]

[Andy Goryachev]

> Introduce a facility, in the form of JUnit5 annotation, to allow for capturing a desktop screenshot of a failed test.
> 
> The primary intent is to be able to debug an intermittent test case, rather than wholesale addition of the new annotation to all the tests.
> 
> The log contains a base-64 encoded screenshot (like this: `data:image/png;base64,iVBORw0KGgoAAAANSUhEU...` )
> so it can be rendered in Safari (Chrome truncates the image possibly due to following a url length limit)
> 
> Example:
> 
> ![jenkins-screenshot](https://github.com/user-attachments/assets/abebd76f-747a-4d6d-a9a6-63c6e9426830)

Andy Goryachev has updated the pull request incrementally with two additional commits since the last revision:

 - cleanup
 - screen capture

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1746/files
  - new: https://git.openjdk.org/jfx/pull/1746/files/5e184b0d..02c185f9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1746&range=03
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1746&range=02-03

  Stats: 199 lines in 2 files changed: 150 ins; 48 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1746.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1746/head:pull/1746

PR: https://git.openjdk.org/jfx/pull/1746