C# Bindings - improved logging (#714)

* added optional support for .NET logging

* bump version and add missing alpha suffix

* avoid creating additional namespace for extensions

* prefer NullLogger/NullLoggerFactory over null-conditional ILogger to avoid errors

---------

Signed-off-by: mvenditto <venditto.matteo@gmail.com>

gpt4all-bindings/csharp/Gpt4All/Extensions/LLPromptContextExtensions.cs

@@ -0,0 +1,26 @@
+using Gpt4All.Bindings;
+
+namespace Gpt4All;
+
+internal static class LLPromptContextExtensions
+{
+    public static string Dump(this LLModelPromptContext context)
+    {
+        var ctx = context.UnderlyingContext;
+        return @$"
+        {{
+            logits_size = {ctx.logits_size}
+            tokens_size = {ctx.tokens_size}
+            n_past = {ctx.n_past}
+            n_ctx = {ctx.n_ctx}
+            n_predict = {ctx.n_predict}
+            top_k = {ctx.top_k}
+            top_p = {ctx.top_p}
+            temp = {ctx.temp}
+            n_batch = {ctx.n_batch}
+            repeat_penalty = {ctx.repeat_penalty}
+            repeat_last_n = {ctx.repeat_last_n}
+            context_erase = {ctx.context_erase}
+        }}";
+    }
+}