Enhancement: Improve input types for instance parameters

[HugoBDesigner]

What would this enhancement be for?

Hammer

Describe your enhancement suggestion in more detail

When using the func_instance_parms entity, you can pick an input type based on FGD input types. This allows for users to define the type of parameter they want to receive for a given variable, such as color255 for colors, studio for models, target_name_or_class for entity names, and so on.

The issue arises in that, when you pick an input type, Hammer will only show the appropriate gizmo in the func_instance if you have no default value set for the func_instance_parms variable. For example, setting the parm1 keyvalue to $test angle works and shows up an angle selection gizmo for that variable in the func_instance, but setting it to $test angle 0 or putting anything as the default value completely removes the gizmo.

Ideally, the instance should show you the gizmo no matter what, but also what the default value is. Additionally, input types like choices have currently no way of setting up what the choices should be, so it only works as an empty dropdown. By allowing users to interact with the proper gizmos for a given input type, it'd make mapping with instances – especially complicated ones with multiple variables – significantly easier and clearer for everyone. It'd also be very helpful if you could either set up a custom, visual-only name for a parameter, or at the very least have the contents of the Comments field carry over to the corresponding instance.