Initial Library Loader for .NET Bindings / Update bindings to support newest changes (#763)

* Initial Library Loader

* Load library as part of Model factory

* Dynamically search and find the dlls

* Update tests to use locally built runtimes

* Fix dylib loading, add macos runtime support for sample/tests

* Bypass automatic loading by default.

* Only set CMAKE_OSX_ARCHITECTURES if not already set, allow cross-compile

* Switch Loading again

* Update build scripts for mac/linux

* Update bindings to support newest breaking changes

* Fix build

* Use llmodel for Windows

* Actually, it does need to be libllmodel

* Name

* Remove TFMs, bypass loading by default

* Fix script

* Delete mac script

---------

Co-authored-by: Tim Miller <innerlogic4321@ghmail.com>

gpt4all-bindings/csharp/Gpt4All/LibraryLoader/LoadResult.cs

@@ -0,0 +1,20 @@
+namespace Gpt4All.LibraryLoader;
+
+public class LoadResult
+{
+    private LoadResult(bool isSuccess, string? errorMessage)
+    {
+        IsSuccess = isSuccess;
+        ErrorMessage = errorMessage;
+    }
+
+    public static LoadResult Success { get; } = new(true, null);
+
+    public static LoadResult Failure(string errorMessage)
+    {
+        return new(false, errorMessage);
+    }
+
+    public bool IsSuccess { get; }
+    public string? ErrorMessage { get; }
+}