[Code-Discussion] New hubs refresh method

[pannal]

We currently use the following method to update hubs when a watch state (watch, unwatch, progress change) changes:

• any hub with do_updates set in HomeWindow.HUBMAP will get refreshed

If "alternative hub refresh" is enabled, we update all hubs.

We have all the necessary information to be smarter about this.

I've had the following idea:

• set the mediaType for each hub definition in HomeWindow.HUBMAP
• when iterating hubs (for the first time), store all of its item's ratingKey (=ID) in a dict as a key, with its value a list of hubIDs (where the ratingKey exists at that point in time)
• supply the ratingKey and itemType of an item for the HomeWindow.updateOnDeckHubs callback
• if item was watched, or progress happened, update all hubs where the item was present (as it should be removed)

Open questions:

• which cases don't we cover here?
• what do we do when an item was unwatched? update all hubs of its type?

Please discuss!

[pannal]

• what do we do when a season or show was watched/unwatched?