RFR: 8350011: Convert jpackage test lib tests in JUnit format [v2]

[Alexey Semenyuk]

> Convert jpackage test library tests in JUnit format. This simplifies running them in IDE.
> 
> Added [JUnitAdapter](https://github.com/openjdk/jdk/pull/23615/files#diff-8719943fb769c04daf413427dc812650763f588cbd0ef6b50cccd11260353c0a) class to simplify running jpackage test-lib tests with JUnit. `JUnitAdapter.runJPackageTests()` will run the jpackage test-lib test as a JUnit test. The test work directory will be created in a temporary directory supplied by JUnit.
> 
> All jpackage test-lib test classes changed to extend `JUnitAdapter`. As they didn't have a default ctor, they were converted accordingly.
> 
> Important: Set `test.src` system property if run these tests outside of jtreg (from IDE) or ad-hoc replace `@@openJdkDir@@` token with the path to local OpenJDK repo at [JUnitAdapter.java:46](https://github.com/openjdk/jdk/pull/23615/files#diff-8719943fb769c04daf413427dc812650763f588cbd0ef6b50cccd11260353c0a).

Alexey Semenyuk has updated the pull request incrementally with one additional commit since the last revision:

  Remove redundant "return"

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23615/files
  - new: https://git.openjdk.org/jdk/pull/23615/files/d0c815d8..ae5ddc79

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23615&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23615&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23615.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23615/head:pull/23615

PR: https://git.openjdk.org/jdk/pull/23615