Improve log search for detected changes

[jakunow]

Currently Cloudimized searches logs in GCP for any detected change in a time window that is static in size and calculated from the moment that all resources have been scanned i.e. script started at 2:00, scanning took 6 minutes, so the logs will be searched in a time window from 1:36 to 2:06.

In some edge cases there might exist log for a given change, but time window doesn't cover it (i.e. change happened at 1:35).