[TASK] Add trait for getArrayRepresentation to populate class

[JakeQZ]

Part of #1440.

[coveralls]

coverage: 70.0% (+0.03%) from 69.969%
when pulling 2a5f36e on task/get-array-rep-class
into 6604f35 on main.

[oliverklee]

Sorry, I missed that this is the PR to review and that #1452 is a draft PR. I'll copy my comments over.

[oliverklee]

I'd strongly prefer the trait to not have an implementation of getArrayRepresentation as this can lead to classes with an incomplete implementation if they implement the trait. (Also, I'd like to avoid parent:: calls.)

Instead, I suggest having a private method getShortClassName(): non-empty-string in the trait. Then we can also build the array from scratch in getArrayRepresentation in the implementing classes, allowing for more concise code.

[JakeQZ]

Instead, I suggest having a private method getShortClassName(): non-empty-string in the trait.

Changed as suggested. Also renamed the trait accordingly.

(Also, I'd like to avoid parent:: calls.)
Then we can also build the array from scratch in getArrayRepresentation in the implementing classes, allowing for more concise code.

In cases where a subclass includes additional properties and the parent also has some properties, it would be more concise not to duplicate filling in the parent's properties in the subclass's implementation.