Allow adding pathfinder goals to an entity (vanilla and custom)

[kangarko]

Is your feature request related to a problem?

N/A

Describe the solution you'd like.

Extending the #2617 to be able for developers to add custom navigation to entities like we do in the NMS class without the need to use NMS.

Describe alternatives you've considered.

Using Citizens plugin. This is good enough but comes with limitations and each entity needs to be wrapped as NPC.

Other

No response

[Nacioszeczek]

https://jd.papermc.io/paper/1.21.1/org/bukkit/entity/Mob.html#getPathfinder()