APIv4 - Add is_active extra field to Domain entity

[colemanw]

Overview

Adds a new calculated field to APIv4 making it easier to get the current active domain.

Before

You could use the magic keyword "current_domain" which is a holdover from APIv3.

After

The magic keyword still works but calculated fields are the way of the future for APIv4 so this new field is consistent with the new approach.

[civibot]

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[eileenmcnaughton]

@colemanw do we use 'is_current' anywhere else in a non-time-centric way in apiv4?

[colemanw]

@colemanw do we use 'is_current' anywhere else in a non-time-centric way in apiv4?

@eileenmcnaughton no, for other entities is_current has a temporal meaning. If it's confusing we could change this field name to something else. Not sure what.

[eileenmcnaughton]

@colemanw yeah - I'm not sure - I'll see if anyone else has any thoughts

[colemanw]

@eileenmcnaughton based on your emoji poll I've renamed this to is_active.