run-tests: update the test case name format Manually typing parenthesis and spaces will be tedious when trying to launch a specific test case. I'm proposing a simpler format that is less hard to remember and type right. There was other possibilities envisaged like `::` or `!`, I think `#` is slight easier to type but I'm open to any suggestion on the new format. Differential Revision: https://phab.mercurial-scm.org/D3556