RFR: 7903373: Add ability to customize test execution using main wrapper plugin [v17]

[Leonid Mesnik]

> The fix adds support of a plugin that customizes test execution.

Leonid Mesnik has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 59 commits:

 - merge
 - CHANGELOG.md updated
 - Renamed TestThreadFactoryProvider.java
 - fixed i28n
 - Updated plugin to implement standard ThreadFactory.
 - removed spaces
 - updated docs and copyrights
 - Added new file.
 - Renamed MainWrapper to TestThreadFactory.
 - removed DriverTest.java
 - ... and 49 more: https://git.openjdk.org/jtreg/compare/2f5f2693...f4e9cc63

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Changes: https://git.openjdk.org/jtreg/pull/136/files
 Webrev: https://webrevs.openjdk.org/?repo=jtreg&pr=136&range=16
  Stats: 416 lines in 17 files changed: 384 ins; 4 del; 28 mod
  Patch: https://git.openjdk.org/jtreg/pull/136.diff
  Fetch: git fetch https://git.openjdk.org/jtreg pull/136/head:pull/136

PR: https://git.openjdk.org/jtreg/pull/136