…collides with droplet

- copy from backup-bareos-test
- add S3 storage device
- add S3 storage daemon
- create test only when the droplet device exists

…s3-test

- configure minio for virtual-host-style requests
- add more log messages sd-droplet device
- add more debugging messages to test

- Fix cmake error when building the documentation, as the
  bareossd-droplet does not exist but get_target_property is called.
- Log the value of the SD_BACKEND_DIR_TO_TEST.
- it would make sense to merge  the two variables
  SD_BACKEND_DIR_TO_TEST and SD_GFAPI_DIR_TO_TEST

- add general-library dependency to libdroplet
- apply cmake-format

… core/