Buy similar: fix mod matching and improve search workflow

[vaisest]

Description of the problem being solved:

This PR removes the need to manually generate the URL and reworks the mod matching. Both of these features are ported over from PoB2.

This also contains tradehash fixes for mods.lua. These aren't actually used here now, but they should still be ported over since it will be necessary for the trader, and in general should just be corrected

Steps taken to verify a working solution:

• Lots of manual testing. There is an insane amount of items that can break this, but I've tried to test a large variety.
• Automated tests ported

Link to a build that showcases this PR:

https://pobb.in/mFd6odfh1yun (has many items and some that use dropdowns on the trade site.

Before screenshot:

After screenshot:

[vaisest]

Notably, crucible mods aren't matched. This probably doesn't matter much because standard, but regardless in the future it can be added once there's an easier way to match mods. The trade site specifically matches against crucible mods, and not just single stats

[vaisest]

This now has all (hopefully) of the PoB2 buy similar stuff. That is, the refactored mod matching, UI which auto generates the URL, and a button for the popup in the items tab

[vaisest]

This also ports PathOfBuildingCommunity/PathOfBuilding-PoE2#2339