[meta] Refactor the Wallpaper feature to prep for A-C migration

[MatthewTighe]

This issue is intended as a top-level issue tracking work to refactor the Wallpaper feature to host its state in the AppStore and initiate the actions it undertakes through the Middleware pattern, as well as abstract Fenix-specific implementations out. This has several benefits:

• architectural consistency
• allows clients to focus on state and interactions instead of implementation details
• creates an abstraction barrier

There are several subissues that will need to be completed for this to be considered done:

• [ ] https://github.com/mozilla-mobile/fenix/issues/25985
• [x] https://github.com/mozilla-mobile/fenix/issues/26029
• [x] https://github.com/mozilla-mobile/fenix/issues/26052
• [ ] https://github.com/mozilla-mobile/fenix/issues/26030
• [ ] https://github.com/mozilla-mobile/fenix/issues/26033
• [ ] https://github.com/mozilla-mobile/fenix/issues/26245

┆Issue is synchronized with this Jira Task

[MozillaNoah]

You could optionally format this issue like the [meta] issues here and here. That way each individual issue has a built-in status indicator without having to click into them.

[MatthewTighe]

You could optionally format this issue like the [meta] issues here and here. That way each individual issue has a built-in status indicator without having to click into them.

Brilliant, thanks for pointing it out! I'll reformat this one if I've got time and definitely remember this for the future

[cpeterso]

Moved to bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1809805

Change performed by the Move to Bugzilla add-on.