Manual overloads for ImGui functions accepting text (#2319)

* wip2

* Implement AutoUtf8Buffer

* reformat

* Work on manual bindings

* restructure

* Name scripts properly

* Update utility functions to use ImU8String

* add overloads

* Add more overloads

* Use ImGuiWindow from gen, support AddCallback

* Use LibraryImport for custom ImGuiNative functinos

* Make manual overloads for string-returning functinos

* Make all overloads with self as its first parameter extension methods

* Fix overload resolution by removing unnecessary

* in => scoped in

* Fix compilation errors

imgui/Dalamud.Bindings.ImGui/Custom/ImDrawCallbackEnum.cs

@@ -0,0 +1,15 @@
+namespace Dalamud.Bindings.ImGui;
+
+public enum ImDrawCallbackEnum : long
+{
+    Empty,
+
+    /// <summary>
+    /// Special Draw callback value to request renderer backend to reset the graphics/render state.
+    /// The renderer backend needs to handle this special value, otherwise it will crash trying to call a function at
+    /// this address. This is useful for example if you submitted callbacks which you know have altered the render
+    /// state, and you want it to be restored. It is not done by default because they are many perfectly useful way of
+    /// altering render state for imgui contents (e.g. changing shader/blending settings before an Image call).
+    /// </summary>
+    ResetRenderState = ImGui.ImDrawCallbackResetRenderState,
+}