Add a custom time stamp option to Incidents

[bakhterets]

We have cases where incidents (minor, major, outage) stay online for a specifc time. E.g. this incident: https://status.otc-service.com/incidents/152

Cloud Eye did work the full time. Therefore, I would like to have the option to adjust the time stamp of the end date.
In the example above, I would e.g. say that the end date was 2024-04-05 13:18 UTC.

Some basic validations should be in place:

End date can not be in the future
End date can not be before the start date
Default (automatically filled) value is "NOW time&date", which can be modified manually by SDMoD
End date can not be before any other status-update timestamp
The possibility to set a custom timestamp should be available for every status change of a incident.