Add ILibcFunction (#1283)

Dalamud/Plugin/Services/ILibcFunction.cs

@@ -0,0 +1,26 @@
+using System.Text;
+
+using Dalamud.Game.Libc;
+
+namespace Dalamud.Plugin.Services;
+
+/// <summary>
+/// This class handles creating cstrings utilizing native game methods.
+/// </summary>
+public interface ILibcFunction
+{
+    /// <summary>
+    /// Create a new string from the given bytes.
+    /// </summary>
+    /// <param name="content">The bytes to convert.</param>
+    /// <returns>An owned std string object.</returns>
+    public OwnedStdString NewString(byte[] content);
+
+    /// <summary>
+    /// Create a new string form the given bytes.
+    /// </summary>
+    /// <param name="content">The bytes to convert.</param>
+    /// <param name="encoding">A non-default encoding.</param>
+    /// <returns>An owned std string object.</returns>
+    public OwnedStdString NewString(string content, Encoding? encoding = null);
+}