Rework installing a collection

[erri120]

Part of #2254.

If you want to test this, you can't use collections that you've added previously. You must delete old collections and re-add them.

• Reworks how collections are installed.
• Fixes exceptions related to dates
• Filters collections by game
• Delete collections (doesn't remove the library items, it just removes the entities)
• Visit collections on Nexus Mods

[Al12rs]

I'll have a go at testing this on Monday, do you have a good collection I should test with?

There are also the schema changes here to keep track of

[erri120]

I'll have a go at testing this on Monday, do you have a good collection I should test with?

Use the most popular Stardew Valley collections.