Backend Filter Options

[HaywardMorihara]

Separated this out from https://github.com/LPGameDevs/EditarrrPublic/issues/98 - see that Issue for historical context.

Add functionality to backend APIs to "filter down" results based on a user query

• [ ] Levels by User Filter Option (only give me levels created by user X - by user name or ID?)
• [ ] Levels Recently Added Filter Option (only give me levels created since)
• [ ] Level Avg Rating Filter Option (only give me levels with an avg rating of 4 or greater)
• [ ] Level Total # Ratings Filter Option (only give me levels with at least 10 ratings)
• [ ] Level Avg Score Filter Option (only give me levels that have an average rating of 4 or greater)
• [ ] Level Total # Scores Filter Option (only give me levels that have at least 50 scores - that have been played 50 times or more)