v2.8.1 - Rebalance update part II

New feature(s) :

• MK IV weapons.
• 21 new agents + search bar.
• Signet of Resilience + Signet of Vitalization.

Bugfix(es) :

• Fixed Healing Power computation.
• Fixed Signet of Thorns + Signet of Thirst.

Other change(s) :

• Various display improvements.