Update docs and RBACs for new Bulk Move Ops

[Steve-Mcl]

closes #4345

NOTE: This can be reviewed and approved independency of the other PRs in the parent issue but I would recommend this is not merged until both #4336 and #4338 have been approved/merged

Description

• Adds RBAC entry for bulk move operations
• Adds instructions and details

Related Issue(s)

Owner #4345 Parent #4290

Checklist

• [x] I have read the contribution guidelines
• [ ] Suitable unit/system level tests have been added and they pass
• [x] Documentation has been updated
  • [ ] Upgrade instructions
  • [ ] Configuration details
  • [ ] Concepts
• [ ] Changes flowforge.yml?
  • [ ] Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • [ ] Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• [ ] Includes a DB migration? -> add the area:migration label

[joepavitt]

Approved, holding off on merge, as requested