RFR: 8320712: Rewrite BadFactoryTest in pure Java [v2]

[Eirik Bjørsnøs]

> Please review this PR which rewrites the BadFactoryTest to pure Java/JUnit. The test is currently implemented using a mix of shell script and a Java main method. 
> 
> Reviewers may notice the following changes:
> 
> - The shell script file `BadFactoryTest.sh` has been retired and jtreg tags moved over to `BadFactoryTest.java`
> - The main method has been replaced with a JUnit `@Test` method
> - The service definition file used to be packaged into a jar file, now the source directory is instead directly added to the classpath using `@library /javax/script/JDK_8196959`
> - The `@summary` tag was updated since the existing summary was slightly confusing
> - To make jtreg happy, the SecurityManager-enabled invocation now runs with `-Djava.security.manager=allow` instead of just `-Djava.security.manager`
> - A sanity check was added to verify that `ScriptEngineManager` can actually find and load `BadFactory`. Such a check would have detected the issue which inspired this rewrite, see  #16585.
> 
> Verified by running:
> 
> 
> % make test TEST="test/jdk/javax/script/JDK_8196959"
>   [..]
>    TEST                                              TOTAL  PASS  FAIL ERROR   
>    jtreg:test/jdk/javax/script/JDK_8196959               1     1     0     0   
> 
> 
> Note that the original issue JDK-8196959 is not available in JBS, so my understanding of what the original test does is based on code inspection.

Eirik Bjørsnøs has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains ten commits:

 - Remove the @library tag, the META-INF service definition file is already on the classpath
 - Merge branch 'master' into badfactory-java-rewritte
 - Add the Java rewrite issue to the @bug list
 - Merge branch 'master' into badfactory-java-rewritte
   
   # Conflicts:
   #	test/jdk/javax/script/JDK_8196959/BadFactoryTest.sh
 - Move jtreg tags from before to after imports
 - Merge branch 'master' into badfactory-java-rewritte
 - Update the @summary to describe the purpose of the test, not the BadFactory
 - Add comment describing the initialization of ScriptEngineManager
 - Implement BadFactoryTest in pure Java

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Changes: https://git.openjdk.org/jdk/pull/16830/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16830&range=01
  Stats: 86 lines in 2 files changed: 24 ins; 60 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/16830.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16830/head:pull/16830

PR: https://git.openjdk.org/jdk/pull/16830