Core/Transports: Fixed crashes caused by invalid leftover transport references

Closes #12282
Core/Spells: Fix Leader of the Pack

Broken with 6b430db910c2cffe49dc1049661c111f164f94f5 because we used the wrong spell...
Merge pull request #12291 from Unholychick/patch-lotp

Core/Spells: Fix Leader of the Pack
DB/SpellGroups: Fix a couple of runtime DB errors from f27821486b0c38e0f92bc719c997f3e9435d7c59
Update SpellAuraEffects.cpp

Cleanup. Already in spell scripts.
Merge pull request #12299 from SeTM/patch-1

Update SpellAuraEffects.cpp
Core/Spells fix 0442ff5c991c351cd6da3c04d1768f756d09fe22

Let it apply only to players
Core/Pets: Fixed pet power regeneration

Closes #12292
Merge pull request #12301 from Unholychick/patch-3

Core/Spells fix 0442ff5c991c351cd6da3c04d1768f756d09fe22
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore