[12670] Add missing spell id 21883

Close scriptdev2/scriptdev2#106

Conflicts:
	src/shared/revision_nr.h
	src/shared/revision_sql.h
[12671] Implement ACTION_T_CHANGE_MOVEMENT for EventAI

This will allow changing the creature movement based on eventAI events.

Requested in scriptdev2/scriptdev2-cata#4

Conflicts:
	src/shared/revision_nr.h
[12672] Implement SCRIPT_COMMAND_SEND_AI_EVENT_AROUND for dbscripts engine

This allows more flexibility in interaction between eventAI and dbscripts

Conflicts:
	src/shared/revision_nr.h