Add a way to preview Typhos templates live in designer

[ZLLentz]

Expected Behavior

There should be some way in the qt designer to tell typhos to load the ui file as if it was a typhos display. This can be live in the edit space as done with the PyDM widgets natively or it can pop out a new widget (as it may need to, given the way macros are used).

Current Behavior

There is no such feature

Possible Solution

• Maybe there can be context menus on typhos widgets that let you select launch args to preview? For example, right-click the typhos widget -> preview in typhos -> enter happi device name -> pops up in a new window
• Maybe you should be able to right-click a widget -> test with device -> pick a happi name -> that widget fills itself (calls add_device) as it would when loading that specific device
• Maybe typhos displays can be given a reload option that allows them to re-read the updated ui file and update in place?

Context

A disappointed question from a template demo + my subsequent impatience waiting for imports etc.