[code-reflection] Integrated: Hat move schema into hat

[Gary Frost]

Step one of migration to Schema

Here we add Schema into hat (from experiments) and add schemas to existing example buffers so we can validate that the layouts are the same. 

At this point the Cascade layouts are identical when generated from existing code and new schema.

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Commit messages:
 - Moving Schema into hat
 - Moving Schema into hat

Changes: https://git.openjdk.org/babylon/pull/154/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=154&range=00
  Stats: 1478 lines in 10 files changed: 823 ins; 627 del; 28 mod
  Patch: https://git.openjdk.org/babylon/pull/154.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/154/head:pull/154

PR: https://git.openjdk.org/babylon/pull/154