Core/Movement: Clean up and improvements on Unit::SetSpeed (#16843)

- Clean up of Unit::SetSpeed (mostly cherry picks from the 6.x branch):
- the opcode sent depends on the unit. until now, MSG_MOVE_SET_* were sent for every units which isn't like retail behavior.
- Removed the unused method parameter "forced" from Unit::SetSpeed
- Renamed Unit::SetSpeed to SetSpeedRate
- Removed the unused method parameter "forced" from Unit::UpdateSpeed
- Added utility method Unit::SetSpeed which take the new flat value.
(cherry picked from commit dc3327f9c5f80c36000356829159c060d916f62b)

# Conflicts:
#	src/server/game/Entities/Unit/Unit.cpp
#	src/server/game/Handlers/MovementHandler.cpp
#	src/server/scripts/EasternKingdoms/ZulAman/boss_akilzon.cpp
#	src/server/scripts/EasternKingdoms/ZulAman/boss_nalorakk.cpp
#	src/server/scripts/EasternKingdoms/ZulAman/boss_zuljin.cpp
#	src/server/scripts/Kalimdor/zone_azshara.cpp
#	src/server/scripts/Kalimdor/zone_durotar.cpp
#	src/server/scripts/Outland/zone_hellfire_peninsula.cpp

1 files changed, 2 insertions, 2 deletions

diff --git a/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp b/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp
index d9b481d7b6d..fded249f9ca 100644
--- a/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp
+++ b/src/server/scripts/EasternKingdoms/SunwellPlateau/boss_felmyst.cpp
@@ -249,7 +249,7 @@ public:
                     me->CastStop(SPELL_FOG_BREATH);
                     me->RemoveAurasDueToSpell(SPELL_FOG_BREATH);
                     me->StopMoving();
-                    me->SetSpeed(MOVE_RUN, 2.0f);
+                    me->SetSpeedRate(MOVE_RUN, 2.0f);
 
                     events.ScheduleEvent(EVENT_CLEAVE, urand(5000, 10000));
                     events.ScheduleEvent(EVENT_CORROSION, urand(10000, 20000));
@@ -530,7 +530,7 @@ public:
         npc_felmyst_vaporAI(Creature* creature) : ScriptedAI(creature)
         {
             me->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE);
-            me->SetSpeed(MOVE_RUN, 0.8f);
+            me->SetSpeedRate(MOVE_RUN, 0.8f);
         }
 
         void Reset() override { }