Utilize Subclass Name for DefaultValue and Expressions

[Fernananas]

Is your feature request related to a problem? Please describe.
Description:
Currently, emx2 allows the use of attributes for setting default values and expressions. However, it would be beneficial to extend this functionality to utilize subclass names as well.

Use Case:
For instance, consider a scenario where a treatment class is extended to create specialized treatments such as diabetes treatment (treatmentdiabetes subclass). In this case, it would be useful to set a default value for the "treatment for" attribute to dynamically reflect the subclass name, providing clarity on the type of treatment in the overview.

Describe the solution you'd like
I propose extending emx2 to support the following:

DefaultValue: Allow the use of the subclass name to automatically set default values for specific attributes. For example, setting a default value for the "treatment for" attribute to reflect the subclass name.
Expressions: Enable the use of the subclass name in expressions to perform operations or comparisons based on the subclass type.

Example of how the feature could be utilized in schema configuration:

  defaultValue: $subclass_name  # Use subclass name as default value
expressions:
  is_diabetes_treatment: "subclass_name === 'treatmentdiabetes'"  # Use subclass name in expressions

Describe alternatives you've considered
I tried using current set-up for defaultvalue and expressions, but Didi

This for ERN -ITHACA:

[mswertz]

Did you try mg_tableclass?

[mswertz]

should be mg_tableclass