Update k8s driver to attach storage to instances

[knolleary]

### Tasks
- [x] Define configuration options for persistent storage (ff.yml)
- [ ] Update k8s driver to attach persistent storage to instances

[hardillb]

First thoughts on required configuration.

This should live under the driver -> options section in the flowforge.yml file.

• storage top level
• storage.enabled set to true to
• storage.storageClass name to use for PVC
• storage.size max size requested

That should work up to 1000 access points (Instances) per EFS filesystem.

We will need a seperate EFS filesystem per 1000

(https://github.com/kubernetes-sigs/aws-efs-csi-driver#createvolume-parameters)

[hardillb]

Assuming we get quotas to work, where should be configure the size?

Should it be at the driver level or the team type?

[joepavitt]

@hardillb any idea on a rough timeframe for when this would be ready?

[hardillb]

Aiming for end of the week

[hardillb]

OK, code is done for this, but I can't test it until I've finished writing the tool that will create new EFS filesystems to test along side it.

Plan is to deploy all this to the scaling cluster tomorrow and test it all before putting it up for Review.