Sentry turrets - Part 4: The sentry turret and its primary systems (#35123)

* Initial commit

* Removed mention of StationAiTurretComponent (for now)

* Prep for moving out of draft

* Fixing merge conflict

* Re-added new net frequencies to AI turrets

* Removed turret control content

* Removed unintended change

* Final tweaks

* Fixed incorrect file name

* Improvement to fire mode handling

* Addressed review comments

* Updated how turret wire panel auto-closing is handled

* Ranged NPCs no longer waste shots on stunned targets

* Fixed bug in tracking broken state

* Addressed review comments

* Bug fix

* Removed unnecessary event call

Content.Shared/Power/Components/ApcPowerReceiverBatteryComponent.cs

@@ -0,0 +1,49 @@
+using Content.Shared.Power.EntitySystems;
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Power.Components;
+
+/// <summary>
+/// Attached to APC powered entities that possess a rechargeable internal battery.
+/// If external power is interrupted, the entity will draw power from this battery instead.
+/// Requires <see cref="Content.Server.Power.Components.ApcPowerReceiverComponent"/> and <see cref="Content.Server.Power.Components.BatteryComponent"/> to function.
+/// </summary>
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
+[Access(typeof(SharedPowerNetSystem), typeof(SharedPowerReceiverSystem))]
+public sealed partial class ApcPowerReceiverBatteryComponent : Component
+{
+    /// <summary>
+    /// Indicates whether power is currently being drawn from the battery.
+    /// </summary>
+    [DataField, AutoNetworkedField]
+    public bool Enabled = false;
+
+    /// <summary>
+    /// The passive load the entity places on the APC power network.
+    /// If not connected to an active APC power network, this amount
+    /// of power is drained from the battery every second.
+    /// </summary>
+    [DataField]
+    public float IdleLoad = 5f;
+
+    /// <summary>
+    /// Determines how much battery charge the entity's battery gains
+    /// per second when connected to an active APC power network.
+    /// </summary>
+    [DataField]
+    public float BatteryRechargeRate = 50f;
+
+    /// <summary>
+    /// While the battery is being recharged, the load this entity places on the APC
+    /// power network is increased by the <see cref="BatteryRechargeRate"/> multiplied
+    /// by this factor.
+    /// </summary>
+    [DataField]
+    public float BatteryRechargeEfficiency = 1f;
+}
+
+/// <summary>
+/// Raised whenever an ApcPowerReceiverBattery starts / stops discharging
+/// </summary>
+[ByRefEvent]
+public readonly record struct ApcPowerReceiverBatteryChangedEvent(bool Enabled);