feature: Improve npcs immunities system

[WeylonSantana]

Description

I'm doing a custom job and I had to add several new spell effects, so I realized that the npcs immunities system is not scalable, problems I found:

Horrible interface - too many checkboxes, and having to add an extra one for every new effect
Unique Tenacity - You can check multiple immunities, but the same tenacity for all of them

The current system allows for a lot of customization, but could be better

Intended Use-Case

One solution, I believe, would be to look at how item effects changed after the daywalkr change.
We need to change the interface to a combobox and nud for tenacity, add a list as happen with the extra effects of items

Objective: an npc, should have different types of immunities with different types of tenacity for them. In addition to avoiding many checkboxes when adding new spell effects.

Duplicate Check

• This enhancement idea is not a duplicate to the best of my knowledge.