Update error handeling

[elYanuki]

The main problem is that we sometimes catch for (Exception ex), this also includes a CCException.

when this generic catch surrounds another method such as a getById or anything else that can throw a CCException: we essentially loose that information that the id was wrong and just throw the less detailed exception thats listed in the catch clause.

• [ ] practically no catch() block should catch for a generic Exception but for something like a NumberFormatException. Possibly multiple try catch blocks are necessary, these can then throw different CCExceptions which make the errors nicer
• [ ] more descriptive exceptions and errors should be added to all the update methods.. for example when a teacher reuqests a confirmation email and the student is not set you get an error instead of a nice CCResponse

[elYanuki]

this is not fully complete, classes such as in the devicetypeRepository still have dangerous generic catches (ones that contain antother function that can throw a CCException) But in the name of clean code: almost every catch should be a specific exception