Implement new Go based Desktop app

This focuses on Windows first, but coudl be used for Mac
and possibly linux in the future.

app/tray/tray_nonwindows.go

@@ -0,0 +1,13 @@
+//go:build !windows
+
+package tray
+
+import (
+	"fmt"
+
+	"github.com/jmorganca/ollama/app/tray/commontray"
+)
+
+func InitPlatformTray(icon, updateIcon []byte) (commontray.OllamaTray, error) {
+	return nil, fmt.Errorf("NOT IMPLEMENTED YET")
+}