add comments to DAO classes in Chickenshock and Finitequiz

[robojones]

DAO

Since the DAOs play an important role in understanding the APIs of our services, they should have Javadoc comments.

DoD

• [x] fields for DAOs and Entities in Chickenshock backend have doc comments
• [x] fields for DAOs and Entities in Finitequiz backend have doc comments

[LeviUniAcc]

dod done