tests: avoid more hard-coded CRLFs in `protocol` sections
- fix regex to not catch CR (from CRLF), in `PORT`, `EPRT`
commands, allowing to use `crlf="yes"` more.
- add `crlf="headers"` mode for `protocol` sections.
To call `subnewlines()` without its force option.
This is the mode used in `data` sections when `crlf="yes"`.
(This confusion may be subject to a future commit.)
- subnewlines: apply CRLF to `HEAD` and `CONNECT` HTTP requests.
- subnewlines: apply CRLF to RTSP requests.
- delete remaining empty `protocol` sections.
Reducing the number of `tests/data/test*`:
- CRLF newlines from 11325 to 10295. (119984 lines total)
- files with mixed newlines from 707 to 656. (1890 files total)
Follow-up to
4d2a05d3fe8ba4db9168b03057029ea5ce7dab77 #19284
Closes #19318