Theme Connector For Snaps classic confinement

@jamesh and/or @kenvandine - whenever you are ready to add the greedy plugs, please add a new topic to the store-requests category.

@jamesh @jdstrand what would trigger the check? simply the presence of “theme” in the snap name? the presence of slots with theme related “content” labels? this will need to be stateful, once a snap is considered a theme it will need to be checked even if it lost the property that made it checked once I think, because themes will be refreshed.

snapd will have to either have a way to trust the store that something that is being installed automatically was vetted or to do the same checks as well

I suppose we could add paired rules like:

  1. snaps whose name begins with gtk-theme- must provide a content interface slot with ID gtk-3-themes.
  2. snaps that provide a content interface ID of gtk-3-themes or gtk-2-themes must be named gtk-common-themes or have a name beginning with gtk-theme-.

(and similar for icon and sound themes).

That would ensure the other validation routines apply to the snap and it can’t stop being a theme snap.