Parent: #142 ## Description The report form asks users to enter duration in seconds. For example, a 15-minute sighting must be entered as 900 seconds. Let users enter a number and choose a familiar unit, such as seconds, minutes or hours. Convert the value to seconds before submitting it so the existing database and API format can remain unchanged. ## Done when Users can enter a sighting duration using a number and unit, and the submitted duration is correctly stored in seconds.