Return reloadContainerOnClick stream after loading

Previously this stream would fire events as soon as the click happened,
now it waits until the HTML is finished loading.
Don't iterate paginator over whole collection

This is necessary in order to add more steps to be run for each
`_get_row_data` query. These queries will be expensive, better to run 10
than 500.
Make importer api call wrappers more DRY