MidnightNameplates 0.11.4.1 - Summon CVar + Plate Ownership Fix

FIX
- MidnightNameplates can manage Blizzard's pet/minion/guardian/totem nameplate source CVars.
- Users no longer need to manually enable Minions in WoW Options.
- Once Blizzard creates the underlying nameplate, Midnight suppresses Blizzard visuals and renders the Midnight plate.
- Disabling source management restores the original remembered CVar values.

TEST
1. WoW Options -> Friendly Player Nameplates -> Minions OFF.
2. /reload.
3. Summons -> Enable summoned-unit controls ON.
4. Friendly Pet / Minion ON.
5. Manage Blizzard minion nameplate sources ON.
6. Warlock/Hunter pet should receive a Midnight plate automatically.
7. No blank Blizzard plate should remain.
8. Disable Friendly Pet / Minion -> custom pet plate disappears.
9. Re-enable -> it returns.
10. Friendly player plates remain unchanged.
11. No Lua/taint/secret-value errors.
