Backend Feature Extensions

[raydatray]

Some features that were originally planned were cut due to time constraints, some other groups had some interesting features I'd like to add, and some of the old code was just downright bad in order to meet a deadline

1. Currently the sports center's opening hours are the same for each day, I'd like to add granularity of the operating hours to be per day
2. Currently a course offering's course sessions must occur all in one room, I'd like to make it so each course session per week could be set to different rooms (What if I have my monday session in the pool and wednesday as dry-land?)
3. Currently it's possible to "double book" a room for a given time slot, this needs to be fixed
4. Some groups had a difficulty type per each course type
5. Some groups had the ability to add profile pictures for user accounts
6. Some groups had the ability to add images for course types, I want the ability to pick an icon per course type
7. Some of the filtering logic is a little jank, I'd like to make dynamic queries properly done

• Extend the sportscenter class such that operating hours can be granular
• Change the association to the room class from course offering to course session
• Extend service logic so that it prevents double booking a room
• Extend the course type class with a difficulty enumeration
• Extend the user accounts class with a profile picture
• Extend the course type class with a icon
• Fix the custom repository implementations