Some feature names used in tests had minor differences compared to
the well-known ones from `curl -V`. This patch syncs them to make test
results easier to grok.
Closes#14183
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
Fixed some issues that caused xmllint failures, added features
and keywords, fixed some quotes and removed some <strip> sections
that unnecessarily limited test checking.
