[FEAT] Standardize Docker images on /opt/scrutiny as the base directory

[AnalogJ]

depends on #222

With the move to influxDB, the omnibus image now runs an influxdb service, which is automatically configured during webserver startup. The problem is that this automatic configuration generates a credential which must be saved so that if/when the container is restarted, the persisted data can still be accessed by the container.

Currently the webapp will try to write the influxdb token to the webapp config file default location. This file may not exist, at which point scrutiny will attempt to create it. However, the parent folder may not exist, in which case the creation will fail (untested).

In the docker image, the default location is /scrutiny/*. For consistency (and safety -- since we eventually want to support non-root deployments), we should migrate all our images (and documentation) to use /opt/scrutiny as the base folder.