feat(game): split nostale apis into safe, unsafe, add contracts usage

feat(game): make item dropped event contain ground item

feat(core): add default states and no errors enum

feat(core): add contract builder

feat(game): add event constraint for IEveryGameResponder Respond

feat(game): add timeouts to contracts

feat(core): add contract builder outline

feat(game): add every game event responder

feat(core): add basics of a contract system

fix(game): make current partner and pet null if pinit does not contain them

fix(packets): make pinit sub packet unknowns nullable

fix(packets): add unknown fields to sc_n packet

chore: use specific errors instead of GenericError

feat(packets): prevent duplicit usings inside source generator

chore: add async analyzer and meet its standards

chore: add ci tests

tests: update, fix tests

feat(packets): make prepared level part of CurrentLevel in PacketStringBuilder similar to PacketStringEnumerator

fix(packets): add missing fields to pinit mate subpacket

fix(game): respect family sub packet nullability