Bug: Annotated types only work in function signatures

[tlambert03]

Describe the bug

create_widget(annotation=Annotated[float, {'max': 5}])

File ~/dev/self/magicgui/magicgui/type_map.py:83, in match_type(tw)
     80 """Check simple type mappings."""
     81 _type = tw.outer_type_
---> 83 if _type in _SIMPLE_ANNOTATIONS:
     84     return _SIMPLE_ANNOTATIONS[_type], {}
     86 if _type is widgets.ProgressBar:

File ~/mambaforge/envs/magicgui/lib/python3.10/typing.py:1651, in _AnnotatedAlias.__hash__(self)
   1650 def __hash__(self):
-> 1651     return hash((self.__origin__, self.__metadata__))

TypeError: unhashable type: 'dict'

problem is that Annotated types are only parsed when members of function signatures...
This should be and will be fixed in the course of #474 ... and is another indication that magicgui is too centered on functions as the unit of input