Add proper Pearl of Tsoatha support

[vaisest]

Description of the problem being solved:

This adds proper pearl of tsoatha support. This includes

• an item db entry
• an option to find pearls in the trader. this has a slot selector and does NOT include the base mod lines. this means that it can be misleading, but otherwise the elemental res and damage will be included in the weight.
• support for supporting item granted skills. this is done by adding a flag appliesToGrantedSkills to the on the ExtraSupport mod, and using that to allow it as an exception.
• support for supporting tree skills. this is done by adding a passive tree slot in the related gem calc code.

It seems that existing ExtraSupport code didn't have protections for duplicate support gems. I had to work around this, and there's a small caveat that they don't show up as (superseded) in the skills tab.

Steps taken to verify a working solution:

• Item tested manually
• tests added
• trader tested manually

Link to a build that showcases this PR:

Before screenshot:

After screenshot:

Note that I removed the elem dam mod here:

[vaisest]

Technically it seems that this should hide the "You cannot socket gems..." label on the skills tab, but it seems like this feature doesn't work anyway on beta so I'm not sure how much of a problem this is

[LocalIdentity]

I fixed 2 tooltip issues. Looks good though

[mcagnion]

Codex found a Trader issue in the Pearl workflow.

The Pearl ring selector only changes RequestQuery()'s local slot, so the selection is lost after query generation. As a result, Stat Value comparisons do not evaluate the fetched Pearl in the selected ring, and Import Item adds the item without equipping it. The focused reproducer passes 3/5 checks; a local patch persisting the effective slot passes 5/5.

Keeping the selected slot name available through evaluation, filtering/tooltips, and import auto-equip resolves the reproduced failures. The interactive UI and an authenticated live trade request were not tested.