[code-reflection] Integrated: Move hat annotations back to core. Some groupied of common classes

[Gary Frost]

Realized I had incorrectly pushed some HAT annotatopns down to optkl. 

Also took opportunity to grouo utility classes into common packages.

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Commit messages:
 - Move hat annotations up to HAT core.  Some grouping of common utility classes

Changes: https://git.openjdk.org/babylon/pull/791/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=791&range=00
  Stats: 161 lines in 104 files changed: 4 ins; 42 del; 115 mod
  Patch: https://git.openjdk.org/babylon/pull/791.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/791/head:pull/791

PR: https://git.openjdk.org/babylon/pull/791