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
The threee tags `<name>`, `</name>` and `<command>` were frequently used
with a leading space that this removes. The reason this habbit is so
widespread in testcases is probably that they have been copy and pasted.
Hence, fixing them all now might curb this practice from now on.
Closes#12028
The "content" is delivered as "body" by curl, but the envelope continues
after the body and the rest of it should be delivered as header.
The IMAP server can now get 'POSTFETCH' set to include more data to
include after the body and test 897 is done to verify that such "extra"
header data is in fact delivered by curl as header.
Ref: #7284 but fails to reproduce the issue
Closes#7748
