Add support for raw (non-formatted) volume in the UI

[slaperche-scality]

Component:

ui

Why this is needed:

We now support formatted and non-formatted volume, but from the UI we can only create formatted volume.

What should be done:

On the volume creation page, add way (a dropdown?) to select the volume mode (either Filesystem or Block, default being Filesystem).

Not sure if we want to expose k8s vocabulary (Filesystem/Block) or another term (Formatted/Non-formatted)? To be defined.

Implementation proposal:

• add a way to get the volume mode from the user
• then use this information to generate the CRD, e.g.:

apiVersion: storage.metalk8s.scality.com/v1alpha1
kind: Volume
metadata:
  name: foo
spec:
  nodeName: master-1
  storageClassName: metalk8s-prometheus
  mode: Block // or   mode: Filesystem
  rawBlockDevice:
    devicePath: "/dev/vdb"

Test plan:

TBD

[gdemonet]

We should make sure the implications of doing this are well explained to the user (maybe a warning when selecting Block mode, or simply a tooltip explaining the two options).