[code-reflection] RFR: Rename @CodeReflection to @Reflect

[Maurizio Cimadamore]

This PR changes `@CodeReflection` into `@Reflect`.

There are lots of changes, but all of them are shallow.

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Commit messages:
 - Rename @CodeReflection to @Reflect

Changes: https://git.openjdk.org/babylon/pull/693/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=693&range=00
  Stats: 1564 lines in 223 files changed: 16 ins; 14 del; 1534 mod
  Patch: https://git.openjdk.org/babylon/pull/693.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/693/head:pull/693

PR: https://git.openjdk.org/babylon/pull/693