feat(Core/CreatureAI): improve npc position during the combat (#3369)

+ tangent equation to find correct angle and distance when moving

+ implemented proper backward

* Improved performance + random angle margin

* chore: add tollerance calculation in instance

* improved LOS checks with movements

* implemented collisions using raycast (imported by TC)

+ improved collision detection for CanReachPositionAndGetCoords

+ improved collision check

+ set correct flags for the backward movement

+ first implementation of slope angle (to improve)

Co-authored-by: Yehonal <yehonal.azeroth@gmail.com>

src/server/game/Spells/SpellInfo.cpp

@@ -1235,6 +1235,11 @@ bool SpellInfo::IsChanneled() const
     return (AttributesEx & (SPELL_ATTR1_CHANNELED_1 | SPELL_ATTR1_CHANNELED_2));
 }
 
+bool SpellInfo::IsMoveAllowedChannel() const
+{
+    return IsChanneled() && (HasAttribute(SPELL_ATTR5_CAN_CHANNEL_WHEN_MOVING) || (!(ChannelInterruptFlags & (AURA_INTERRUPT_FLAG_MOVE | AURA_INTERRUPT_FLAG_TURNING))));
+}
+
 bool SpellInfo::NeedsComboPoints() const
 {
     return (AttributesEx & (SPELL_ATTR1_REQ_COMBO_POINTS1 | SPELL_ATTR1_REQ_COMBO_POINTS2));