Implement SteamGridDB filter settings

[Lucki]

This allows to set the humor and nsfw for api calls to SteamGridDB. They have three states:

• Only include filtered images
• Exclude filtered images (default)
• Show all results

Additionally I've completed the size array with new supported sizes.

I'm not entirely sure what the null size is about. It only makes another list entry with scrambled sizes in various formats in it.