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
Adds these test cases:
383 - simple single command line option
384 - reading it from stdin
385 - getting two --json options on command line
386 - --next works after --json
Closes#8314