Add temporal filter to GetDataAvailability requests?

[tslawecki]

Downloading of results from large GetObservation requests can be time-consuming, and it would be useful to provide the user with feedback on the progress of their request. One way 52N SOS might help is to allow a temporal filter to be placed on the GetDataAvailabilityRequest to allow the querying individual/software to assess roughly how large a given retrieval might be to set expectations and perhaps strategy, such as breaking down the retrieval into smaller subretrievals.

[TheTrailblazer09]

I am on it