Progress toward issue #2003.
Includes design from design doc PR #1578

Use init containers to create configuration for Ceph mons. There are 3
init containers in this design:
 1. Using the Rook image, call the Rook binary to create Ceph config
files ultimately stored in a k8s EmptyDir which is shared between all
containers in a mon pod.
 2. Leaving room to use the Ceph-versioned image in the future, call
`monmaptool` to generate the monmap, stored in a shared config dir.
 3. Leaving room to use the Ceph-versioned image in the future, call
`ceph-mon --mkfs ...` to set up the mon filesystem on the host's disk.

Once this init is run, the main mon daemon is run. Leaving room to use
the Ceph-versioned image in the future, call `ceph-mon --foreground ...`
to run the Ceph mon.
Signed-off-by: Blaine Gardner <blaine.gardner@suse.com>