Server Favorites

[helloer]

As a user I want to keep list of my favorite servers in the lobby list and manage it in an easy way.

• The easiest way to implement it would be by storing an array of ip:port and then filtering out rest of the servers from lobby list
• Easy way to add/remove servers from the list (heart/unheart icon next to server flag?)
• Toggle button to show only favorites (next to filter/refresh buttons?)
• Auto-save list to a file(json?) and then load it on startup