WIP: Add widget popup actions

[Destroy666x]

Also makes DisplayMessage's text selectable.

WIP because it unfortunately doesn't work outside of the Advanced Scene Switcher settings window - it hangs OBS. I learned later that global popups may be (still) impossible to achieve.

So not too sure what to do with it - maybe you'll have a better idea @WarmUpTill. For now submitting as PR to free stash. If not then I guess this could be redone when the'll make this possible.

[WarmUpTill]

Thanks!
I will try to have a look during the weekend.

WIP because it unfortunately doesn't work outside of the Advanced Scene Switcher settings window - it hangs OBS

Did you maybe have a dialog in mind like it is used in the variable action with the "ask for input option"?

If so this code snippet might help.

[Destroy666x]

Thanks, more or less, so you're saying the non-modal class is made to work anywhere in OBS? If so, I'll take a look later today.

[WarmUpTill]

I think what might be causing the crashes is that you are trying to open a modal dialog from a non-UI thread.
You might have to use obs_queue_task() to do that.

The non-modal dialog might not run into this issue, but to be honest I am mostly guessing here.