Specify past date/time arguments to collect logs

The GitLabSOS in nature collects logs from the point that it was executed.

There are often instances where customers know when they experienced an intermittent issue ie. performance problems or when they performed an operation a week ago ie. indexing ElasticSearch.

In these cases, we normally have to ask for the *.gz files.

It would be handy to be able to specify a past date/time argument to collect logs from a particular timeframe ie. something like:

gitlabsos --from <DATE> --to <DATE>

The date could either be UNIX/Epoch or ISO8601.