Implemented loot filter

[FominArtmind]

Motivation: loot filters are important part of the games with reach loot system. For "the origin" Diablo 2 many third party software has been specifically implemented for the purpose, as for many more modern games, they have provided loot filter from a box. For Valheim (with item cluttering being one of the biggest not solved problem of the game design in it), the possibility to reduce potential cluttering is vital.

What has been implemented:

• "Use Loot Filters" configuration setting to turn loot filters on/off
• configuration file "lootfilters.json" that allows users to create/update lists of blacklist/whitelist loot filters
• logic of filters usage

Blacklist filters can be configured to prevent specific items from dropping completely or to auto convert the matching items to materials. Whitelists prevent items from matching to any blacklist.
Each filter has the following configuration properties:

• "Items" - list of item names to match
• "DropMaterials" - whether to convert the item to materials or not drop at all
• "Rarities" - what item rarities are affected
• "Quality" - what item qualities are affected
• "Distance" - distance from the center of the world the filter starts to be applied from

Not implemented but potentially usefull to implement is "Day" property which can control day of the world the filter starts to be applied from (to match CreatureLevelControl alternative world level setting).

Backward compatibility: similar to ItemName filter, requires FominArtmind:pr-item-name-in-magic-item, FominArtmind:pr-quality-of-items, FominArtmind:pr-loottables-distance-config, FominArtmind:pr-changed-item-gating-to-replacing-with-materials to be accepted first to avoid merge conflicts.