Split a bit of backend code

internal/app/connection.go

@@ -0,0 +1,28 @@
+package app
+
+import (
+	"fmt"
+
+	"github.com/wailsapp/wails/v2/pkg/runtime"
+	"go.mongodb.org/mongo-driver/bson"
+)
+
+func (a *App) OpenConnection(hostKey string) (databases []string) {
+	client, ctx, close, err := a.connectToHost(hostKey)
+	if err != nil {
+		fmt.Println(err.Error())
+		return nil
+	}
+	databases, err = client.ListDatabaseNames(ctx, bson.M{})
+	if err != nil {
+		fmt.Println(err.Error())
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:    runtime.ErrorDialog,
+			Title:   "Could not retrieve database list",
+			Message: err.Error(),
+		})
+		return nil
+	}
+	defer close()
+	return databases
+}