Core: Add rest of checks from SendListInventory to BuyItemFromVendorSlot
Core/Achievements: Implement criteria type ACHIEVEMENT_CRITERIA_TYPE_ON_LOGIN and criteria requirements ACHIEVEMENT_CRITERIA_REQUIRE_NTH_BIRTHDAY and ACHIEVEMENT_CRITERIA_REQUIRE_KNOWN_TITLE. Fixes anniversary achievements.

By @Schmoozerd
Core/Achievements: Use ACE_OS::localtime_r instead of localtime in my previous commit for thread safety.

Thanks to @Shauren
Merge pull request #11568 from Rochet2/VendorChecks

Core: Add rest of checks from SendListInventory to BuyItemFromVendorSlot
Core/Auras: Implemented SPELL_AURA_MOD_COOLDOWN

Closes #9671
Authserver / Worldserver: Fix warnings about unused variables
Remove whitespaces from previous commit