Fix pets lagging behind and despawning by slightly adjusting speed
if too far from owner.

Closes #8740
Update src/server/game/Entities/Unit/Unit.cpp

Fix crash on "tame pet"
Update src/server/game/Entities/Unit/Unit.cpp

Code style cleanup
Update src/server/game/Entities/Unit/Unit.cpp

Revert codestyle changes to cut down on calls to GetCharmerOrOwner()
Merge pull request #8753 from MrSmite/Pet_SpeedFix

Fix pets lagging behind and despawning