To make special newlines more explicit and visible.
Mostly in `<protocol>` sections, some in `<data*>` and `<upload>`.
Reducing the number of `tests/data/test*`:
- CRLF newlines from 21535 to 11337.
- files with mixed newlines from 1335 to 707.
Also delete empty `<protocol>` sections.
Closes#19284
After 7cf8414fab#12862, `VAR=` no longer
removes the env variable, but sets it to an empty/blank value instead.
To remove an env, `VAR` shall be used (without the assigment operator.)
`SSL_CERT_FILE`, `CURL_HOME`, `HOME`, `XDG_CONFIG_HOME`, were added
before the change above. Make tests unset these envs again, as their
commit messages suggest, instead of blanking them. It does not change
the outcome of the tests.
Ref: 764e4f066d#8213
Ref: e992770e8d#6600
Folllow-up to 7cf8414fab#12862
Cherry-picked from #17988Closes#17994
To reduce the risk that the user running the tests has a .curlrc present
that messes things up.
Support 'option="no-q"' for the <command> tag to switch it off on demand.
Use this new feature in test 433 and 436.
Ref: #13284Closes#13387
