Results page number not reset when context changes

[murphyke]

The results page number is not reset when the context changes. If the number of new results pages is smaller than the previous, this can result in the query "hanging" from the user's point of view -- the "Loading Results" overlay stays up forever, although the preview endpoint payload is fetched.

To reproduce:

• Run the harvest-openmrs demo with avocado==2.4.1 and serrano==2.4.3.
• Click Results to obtain all unfiltered rows.
• Click Next> to go the second page of results.
• Click Query and under Patient Details choose and apply a query filter of MRN000001.
• Click Results

I wonder if a similar thing might happen if columns were removed from the DataView such that the number of output pages decreased ....