BatteryWeaponPowerCell tweaks (#33500)

* BatteryWeaponPowerCell tweaks

* add update ammo ev & shuttle guns tweaks

* MilonPL requested changes

* revert changes in OnPowerCellChanged

* Add events to get charge info & change current charge

---------

Co-authored-by: Nemanja <98561806+EmoGarbage404@users.noreply.github.com>

Content.Server/Power/Components/BatteryComponent.cs

@@ -38,4 +38,30 @@ namespace Content.Server.Power.Components
     /// </summary>
     [ByRefEvent]
     public readonly record struct ChargeChangedEvent(float Charge, float MaxCharge);
+
+    /// <summary>
+    ///     Raised when it is necessary to get information about battery charges.
+    /// </summary>
+    [ByRefEvent]
+    public sealed class GetChargeEvent : EntityEventArgs
+    {
+        public float CurrentCharge;
+        public float MaxCharge;
+    }
+
+    /// <summary>
+    ///     Raised when it is necessary to change the current battery charge to a some value.
+    /// </summary>
+    [ByRefEvent]
+    public sealed class ChangeChargeEvent : EntityEventArgs
+    {
+        public float OriginalValue;
+        public float ResidualValue;
+
+        public ChangeChargeEvent(float value)
+        {
+            OriginalValue = value;
+            ResidualValue = value;
+        }
+    }
 }