[code-reflection] Integrated: For bld.java added javac diagnostics to JavaResult

[Gary Frost]

Mostly cosmetic changes to Script.java and bld.java. 

Specifically now we show colorized 'diagnostics' from javac. So errors RED in output.

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Commit messages:
 - For bld.java added javac diagnostics to JavaResult

Changes: https://git.openjdk.org/babylon/pull/408/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=408&range=00
  Stats: 222 lines in 2 files changed: 123 ins; 33 del; 66 mod
  Patch: https://git.openjdk.org/babylon/pull/408.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/408/head:pull/408

PR: https://git.openjdk.org/babylon/pull/408