[feature request] allow some kind of type annotations besides relying on the default argument type

[ophiry]

currently, marking a parameter as list requires adding a default list value for it - but this is problematic when the function is also used from regular code (the list may change over time).

additionally, sometimes it's desirable to set a type for a parameter, but keep it mandatory

having something like:

@command('function_name', types={'p1':list})
def function_name(p1,p2):
    pass

can solve this