Add IJobGauges (#1265)

Dalamud/Plugin/Services/IJobGauges.cs

@@ -0,0 +1,21 @@
+using Dalamud.Game.ClientState.JobGauge.Types;
+
+namespace Dalamud.Plugin.Services;
+
+/// <summary>
+/// This class converts in-memory Job gauge data to structs.
+/// </summary>
+public interface IJobGauges
+{
+    /// <summary>
+    /// Gets the address of the JobGauge data.
+    /// </summary>
+    public nint Address { get; }
+
+    /// <summary>
+    /// Get the JobGauge for a given job.
+    /// </summary>
+    /// <typeparam name="T">A JobGauge struct from ClientState.Structs.JobGauge.</typeparam>
+    /// <returns>A JobGauge.</returns>
+    public T Get<T>() where T : JobGaugeBase;
+}