Cognite Infield: Offline mode to allow for manual timestamp entry

Thanks @rsiddha - will bring this feedback into our “internet connection” discovery work. 

Also, if a user makes an entry in a checklist (In InField) and closes the checklist, then realizes that a mistake was made (for instance fumble fingered an extra digit), re-opens the checklist and and corrects the value, the timestamp advances all of the entries on that checklist to “now” which is then incorrect.  Please allow the user to make corrections to data without changing the original timestamp. The user should also be able to mannually select a timestamp in the past if needed.  This would also apply if there was a network outage and the checklist was done on paper to be entered when the network connection is restored.