DateRangePicker3 allows end time to be less than start time for single date selection

[evansjohnson]

Steps to reproduce

• https://blueprintjs.com/docs/#datetime2/date-range-picker3
• Turn on allow single day range
• Select same date range
• Modify time such that end time is less than start time

Actual behavior

Able to select a "negative" time range

Expected behavior

End time range should be constrained to a valid selection range

Possible solution

• Only allow selecting a time greater than (or maybe greater or equal to) the start time
• Always update value such that the earlier date is first