Empty artists added to favorite

[maboroshin]

Platform:

nuclear-fd06a3, Windows 10

Description of the issue:

1. Press the favorite button of an empty artist. Related: https://github.com/nukeop/nuclear/issues/1427
2. An empty artist will appear in the Favorite Artists tab.
3. Selecting Remove will not remove this artist.
4. An empty array is registered inconfig.json :

		"artists": [
			{}
		],

Expected correct behavior:

• Prevent empty artists from registering.
• Automatically delete empty artists.

[aditdesai]

@nukeop I would like to work on this

[sferra]

This issue should be fixed, since #1427 is fixed.