Suggest and validate input parameter options for actions in Designer

PROBLEM
In Designer, people creating an action have no idea what to type and what makes sense depending on the chosen slot.

TODO

• In Designer actions, suggest [if technically possible only valid options for current slot, otherwise all options] for input parameter
• When saving, if selected option is not valid for the selected slot, a validation error is shown:

  Current input parameter is not valid for the current slot. [-If technically possible- Possible options: ...]