Item fixes

[DantestyleXD]

This PR contains a series of changes to:

• Improve inventory management on database interactions by eliminating the presence of duplicates within the charaglobalitem table and improving the reading of items in dedicated bags;
• Implement crystal management in the appropriate bag;
• Improve the response between server and client on the already existing item management functions;
• Add management for the buyback of items sold to vendors, with a proper rebase to avoid gaps within the buyback list;
• Improve code readability in some points where the result of a DB query was being read.

ADDON: Print more than 200 args with value = 0 delay shop events... now it will print only args with value > 0