Reduce dialog count

[BigETI]

• [x] Remove connect dialog and add user name input to main form

[BigETI]

It will have an option to show the username dialog. By default it won't be shown before connecting to a server.

[BigETI]

https://github.com/BigETI/SAMPLauncherNET/commit/6708f5b2dc63900ac67eed6f6d6b7ae1426edacb