Add parameters/arguments to specific tests

[D3vil0p3r]

What would you like to be added:
@popey @flexiondotorg A very useful and flexible feature to add could be the adding of the possibility to pass arguments/parameters to be used inside test files. For example, a Linux distro can allow you to select GNOME or KDE as Desktop Environment.
Instead of create two separated files for tests, it could be useful to have a single file, with if statement, to manage something like:

if $1 == "gnome" (so if you passed "gnome" as input argument of "quicktest" command, run "qt_send_key_combo "down"", otherwise just press enter.

Why is this needed:
It provides huge flexibility on performing tests with one single file where to test scenarios with different conditions.

Additional context: