[code-reflection] Integrated: Avoid Trxfmr constructor, use static factory of method

[Gary Frost]

Added static factory Trxfmr.of method and some fluent helpers for common tasks.

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Commit messages:
 - Avoid Trxfmr constructor. Added static factory of method also some fluent helpers

Changes: https://git.openjdk.org/babylon/pull/810/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=810&range=00
  Stats: 393 lines in 13 files changed: 22 ins; 299 del; 72 mod
  Patch: https://git.openjdk.org/babylon/pull/810.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/810/head:pull/810

PR: https://git.openjdk.org/babylon/pull/810