Passing the option as-is to libcurl is fine, but checking that the file
exists allows the tool to better provide a helpful message.
This now done for the following options:
--cacert, --crlfile, --knownhosts, --netrc-file, --proxy-cacert amd
--proxy-crlfile
Bonus: bail out properly on OOM errors in the --cert parser.
Reported-by: Wesley Moore
Fixes#19583Closes#19585
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
