Add to Group menu item doesnt add favorite

[jirkapok]

Steps to reproduce:

1. Having two groups "aaa" and "bbb" and favoriteA in group bbb
2. Open connection for favoriteA
3. When connection is active select from menu Groups > Add current connection to...

Result:

• The favorite isnt added to expected group, also verified after application restart
• Applies to both persistence types

Dev. note: Todo in MainForm GroupAddToolStripMenuItem_Click method.

[jirkapok]

The same behavior applies to the create group from connections menu.