task: #3594136 Add test coverage for daterange fields

A daterange shows up in Views as two ordinary date filters, one for the start and one for the end, so the cache plugins should already handle it. These tests confirm that for the < and > plugins: filtering on the start column, on the end column, and on all-day ranges (which end at 23:59:59, so they're the most likely to be off by a day). No plugin changes were needed.

Adds daterange helpers and the datetime_range module to the shared test base.

Closes #3594136