RFR: 8300829: Make CtwRunner available as an independent tool

[Joshua Cao]

1. Create an independent jar file with CtwRunner as the main class to make it easier to run
2. Output the class files directly into the destination directory. Currently, CTW expects a `wb.jar`, but the jtreg tests that use CTWRunner has class files outside of a jar.
3. Introduce `sun.hotspot.tools.ctwrunner.ctw_extra_args` option to pass extra arguments to CTW. Arguments are comma separated because working with spaces in bash can be kind of awkward, but I'm open to changing this part.

### Motivation
CTWRunner is a wrapper around CTW that will continue compiling beyond failure. It can be useful for testing compilation with certain flags. For example, one could run


JAVA_OPTIONS="-Dsun.hotspot.tools.ctwrunner.ctw_extra_args=-XX:+StressLCM,-XX:+StressGCM" ./ctwrunner.sh modules:java.base


To test compiling the java.base module with `-XX:+StressLCM -XX:+StressGCM`. This is advantageous over uses CTW because we can see the full list of crashes for the entire module.

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Commit messages:
 - 8300829: Make CtwRunner available as an independent tool

Changes: https://git.openjdk.org/jdk/pull/13344/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13344&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300829
  Stats: 109 lines in 3 files changed: 68 ins; 35 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13344.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13344/head:pull/13344

PR: https://git.openjdk.org/jdk/pull/13344