RFR: 8336470: Source launcher should work with service loader SPI in unnamed module [v15]

[Christian Stein]

> Please review this change adding a missing resource file test to the `MemoryClassLoader::findResource` override in order to resolve all files beneath the source root path in source launch mode - analog to what was already implemented for `MemoryClassLoader::getResource`.
> 
> With this change applied, files in `META-INF/services/` are resolved; allowing services providers being supplied in source form.

Christian Stein has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 12 additional commits since the last revision:

 - Merge branch 'openjdk:master' into JDK-8336470-source-launcher-get-resources
 - Revert change after JDK-8356678 being addressed
 - Prevent FileSystemException on Unix-based file systems
 - Prevent NPE by removing redundant check
 - Removed redundant catch block
 - Catch and rethrow IO exception
 - Fix interim javac compilation
 - Reuse internal resource resolver and remove confusing comment
 - Update copyright year
   
   [skip ci]
 - User copyright text w/o `"Classpath" exception`
   
   [skip ci]
 - ... and 2 more: https://git.openjdk.org/jdk/compare/66dbbfe2...11956f24

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20193/files
  - new: https://git.openjdk.org/jdk/pull/20193/files/be6cb82b..11956f24

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20193&range=14
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20193&range=13-14

  Stats: 57606 lines in 1849 files changed: 36666 ins; 11655 del; 9285 mod
  Patch: https://git.openjdk.org/jdk/pull/20193.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20193/head:pull/20193

PR: https://git.openjdk.org/jdk/pull/20193