When a multiplex connection (h2/h3) is shutdown by the server, the
reported number of parallel transfers allowed drops to 0.
Determine that when the last transfer is done and terminate the
connection instead of keeping it in the cache.
We detect the drop to 0 also when we try to reuse such a connection, but
if we know this at the time the last transfer is done, we better
terminate it right away.
Have a consistent trace logging to this with the connections current
hostname and port. Adjust test expectations to carry port numbers.
Closes#17884
Check responsiveness of http/3 server when running.
Also, a test case with http/2 or http/3 server requirement
now implicitly drags in a 'http' server and we need no longer
mention that in testdata.
Closes#15058
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
