Allow setting apps to be opened without prompting for certain MIME types

[wjt]

On Endless OS, the "eos-gates" tool which is supposed to show a dialog like the following when you try to open a .deb, .rpm or .exe, since such packages cannot be installed or executed on Endless OS:

However because there are other handlers for the application/x-deb MIME type, the app chooser dialog is shown when one downloads a .deb and opens it from the browser:

I believe that after accepting the default 3 times, it would be used without prompting.

It would be useful for the distro to be able to override the default behaviour, so that across all apps, or failing that across a manually-created list of popular web browsers, Gates opens by default without prompting for this mime type.

This is a cousin of #471 because, as far as I can tell, this information lives in the permission store.

[JakobDev]

Maybe adding a "Use this App as default" Check Box would be an option

[wjt]

Such a checkbox wouldn't help with my goal here: on our distro I want this dialog to never appear for this MIME type.

(The portal remembers what you choose and if you pick the same app for a mime type 3 it stops asking.)