Merge bitcoin#22437: test, refactor: add GetTransaction() coverage, improve rpc_rawtransaction

387355b test, refactor: rpc_rawtransaction PEP8 (Jon Atack)
7d5cec2 refactor: separate the rpc_rawtransaction tests into functions (Jon Atack)
409779d move-only: regroup similar rpc_rawtransaction tests together (Jon Atack)
d861040 test: remove no longer needed (ASCII art) comments (Jon Atack)
14398b3 test: add and harmonize getrawtransaction logging (Jon Atack)
85d8869 test: run 2nd getrawtransaction section with/without -txindex (Jon Atack)
0097740 refactor: txid to constant in rpc_rawtransaction to isolate tests (Jon Atack)
8c19d13 refactor: dedup/reorg createrawtransaction sequence number tests (Jon Atack)
7f07359 Test src/node/transaction::GetTransaction() without -txindex (Jon Atack)

Pull request description:

  Following up on bitcoin#22383 (review), this pull adds missing `src/node/transaction::GetTransaction()` test coverage for combinations of `-txindex` and `blockhash` and does some refactoring of the test file.

ACKs for top commit:
  mjdietzx:
    reACK 387355b
  josibake:
    reACK bitcoin@387355b
  MarcoFalke:
    Approach ACK 387355b 🔆

Tree-SHA512: b47c4ff87d69c61434e5729c954b338bc13744eddaba0879ca9f5f42243ba2cb4640d94c5f74de9f2735a8bf5e66b3d1c3bd3b7c26cd7324da7d3270ce87c6fd

Author: MarcoFalke