Store workspace size used for a given workspace instance

[atduarte]

Is your feature request related to a problem? Please describe

We are unable to determine which workspace size (or class, as it is mentioned in the code) was used for a given workspace instance. This a problem as different workspace sizes may have different storage capacities, and impacts our reporting capabilities.

Describe the behaviour you'd like

Having one more column on d_b_workspace_instance with the workspace size name.

Describe alternatives you've considered

N/A

Additional context

N/A