Add flag to arv-put to set a trash_at date
The use case would be for when sequencers finish uploading to arvados, we can set the timer to delete that data after some designated time period.
Trash times could be specified in 2 ways:
1. Absolute datetime: Could be accepted from a param like
--trash_at "YYYY-MM-DD HH:MM"
2. Relative times: Could be accepted from a param like
--trash_after XX (where XX is number of days)
Both parameters would be mutually exclusive.
The accepted format for absolute datetimes would be the one described at https://en.wikipedia.org/wiki/ISO_8601
The accepted relative time parameter unit will be number of days (to be converted to amount of seconds) and it should take into account possible timezone changes.
The relative trash time should take note of the upload finish process datetime. When uploading using the "rsync mode", it should update the trash_at value when checkpointing.