Instead of providing a fixed single synthetic response in the test
server itself. To allow us to better use *different* directory listings
in different test cases. In this change, most listings remain the same
as before.
The wildcard match tests still use synthetic responses but we should fix
that as well.
Updated numerous test cases to use this.
Closes#14295
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
