Make health correctly recalculate its cached values when the entity changes owner.

Following rP22767, the ModifierManager no longer sends ValueModificationMessages when an entity changes owner to/from INVALID_ENTITY. This happens in particular when the entity is renamed.

For now, components must check on their own in OwnershipChanged.

Reported By: Freagarach

Patch By: Angen

Reviewed By: wraitii

Fixes #5588

Differential Revision: https://code.wildfiregames.com/D2286