Add ability to view all items

[ValancedBreakfast]

It would be nice to have a screen to view all items in the entire game (all types, all heroes, all events, all at once). Preferably this screen would allow the filter options that the hero screen currently have to allow filtering by events and (un)selected.

This will allow user to see how many legendaries they are missing and other similar comparisons across all items. Useful for planning out event boxes now that the new no duplicate rules have been applied to the loot box algorithm.