Core/Creatures: implemented most movement related static flags and migrated existing movement data into static flags

* implemented CREATURE_STATIC_FLAG_AQUATIC - creatures cannot leave liquids
* implemented CREATURE_STATIC_FLAG_AMPHIBIOUS - creatures can enter and leave liquids but remain on the ocean floor when swimming is not enabled until engaged
* implemented CREATURE_STATIC_FLAG_FLOATING - creatures have their gravity on spawn / reset disabled
* implemented CREATURE_STATIC_FLAG_SESSILE - creatures are rooted in place
* implemented CREATURE_STATIC_FLAG_CAN_SWIM - creature can swim in liquids
* implemented CREATURE_STATIC_FLAG_3_CANNOT_SWIM - Amphibious creatures cannot toggle on swimming
* implemented CREATURE_STATIC_FLAG_3_CANNOT_TURN - Creatures cannot turn at all
* implemented CREATURE_STATIC_FLAG_4_PREVENT_SWIM - Amphibious creatures won't toggle on swimming until their victim starts leaving the ocean floor
* partially implemented CREATURE_STATIC_FLAG_3_CANNOT_PENETRATE_WATER
* deprecated CREATURE_FLAG_EXTRA_NO_MOVE_FLAGS_UPDATE as this flag was a hackfix to a wrong implementation that is now gone
Port From (https://github.com/TrinityCore/TrinityCore/commit/c541eda54d7e0dddeec329a6beac2948e0b0a40b)

Source/Game/Movement/Generators/HomeMovement.cs

@@ -60,11 +60,9 @@ namespace Game.AI
 
             if (movementInform && HasFlag(MovementGeneratorFlags.InformEnabled))
             {
-                if (!owner.HasCanSwimFlagOutOfCombat())
-                    owner.RemoveUnitFlag(UnitFlags.CanSwim);
-
                 if (owner.IsStateRestoredOnEvade())
                 {
+                    owner.InitializeMovementCapabilities();
                     owner.SetSpawnHealth();
                     owner.LoadCreaturesAddon();
                     owner.LoadCreaturesSparringHealth();

Source/Game/Movement/Generators/PathGenerator.cs

@@ -155,7 +155,7 @@ namespace Game.Movement
                 BuildShortcut();
                 bool path = _source.IsTypeId(TypeId.Unit) && _source.ToCreature().CanFly();
 
-                bool waterPath = _source.IsTypeId(TypeId.Unit) && _source.ToCreature().CanSwim();
+                bool waterPath = _source.IsTypeId(TypeId.Unit) && _source.ToCreature().CanEnterWater();
                 if (waterPath)
                 {
                     // Check both start and end points, if they're both in water, then we can *safely* let the creature move
@@ -850,7 +850,7 @@ namespace Game.Movement
             if (_source.IsTypeId(TypeId.Unit))
             {
                 Creature creature = _source.ToCreature();
-                if (creature.CanWalk())
+                if (!creature.IsAquatic())
                     includeFlags |= NavTerrainFlag.Ground;
 
                 // creatures don't take environmental damage