Allow querying datetime values with time accuracy

[rowanseymour]

Currently we allow dates to have time but then just ignore it. Should work like..

created_on = 01-12-2021 - should match 2021-12-01T00:00 <= created_on < 2021-12-02T00:00

created_on = 01-12-2021 14:00 - should match 2021-12-01T14:00 <= created_on < 2021-12-02T14:01

[rowanseymour]

If we fixed this, we could use contact querying to show the contacts scheduled for a given campaign event - turn the count of fires into a link to a contact search.