Resolve "prepare docker volumes for services"

Closes #153 (closed)

Replace hard-coded mount paths of data-generating services with environment variables to increase flexibility. For every service that can create data we define a docker volume that can be used instead of the local data directory.

Can be tested by:

• setting <SERVICE>_PERSISTENCE_VOLUME to local path that was originally used (see below, except for MinIO)
• optionally, trying another path to a directory with write permissions for user UID, e.g. /tmp/...
• set <SERVICE>_PERSISTENCE_VOLUME= (empty) or use default values from .env.example to use pre-defined docker volumes.

.env on stage and prod needs to be updated before merging

set

• OBJECT_STORAGE_PERSISTENCE_VOLUME=/mnt/tsm/minio/data/
• VISUALIZATION_PERSISTENCE_VOLUME=./data/grafana
• MQTT_PERSISTENCE_VOLUME=./data/mosquitto
• FROST_PERSISTENCE_VOLUME=tomcat-context
• CRON_PERSISTENCE_VOLUME=./cron
• DATABASE_PERSISTENCE_VOLUME=database