Update lsp to have set root path

compiler/NubLang.LSP/SetRootPathCommandHandler.cs

@@ -0,0 +1,31 @@
+using MediatR;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Extensions.LanguageServer.Protocol.Workspace;
+
+namespace NubLang.LSP;
+
+public class SetRootPathCommandHandler(WorkspaceManager workspaceManager) : ExecuteCommandHandlerBase
+{
+    protected override ExecuteCommandRegistrationOptions CreateRegistrationOptions(ExecuteCommandCapability capability, ClientCapabilities clientCapabilities)
+    {
+        return new ExecuteCommandRegistrationOptions
+        {
+            Commands = new Container<string>("nub.setRootPath")
+        };
+    }
+
+    public override Task<Unit> Handle(ExecuteCommandParams request, CancellationToken cancellationToken)
+    {
+        if (request is { Command: "nub.setRootPath", Arguments.Count: > 0 })
+        {
+            var newRoot = request.Arguments[0].ToString();
+            if (!string.IsNullOrEmpty(newRoot))
+            {
+                workspaceManager.SetRootPath(newRoot);
+            }
+        }
+
+        return Unit.Task;
+    }
+}