RBAC changes for cbbackupmgr (Analytics)

As described in DOC-5285, cbbackupmgr now supports Analytics. All the other required documentation has been done, but some changes need to be made to the RBAC Roles page.

The Data Backup role needs to have the following extra permissions:

[analytics], [select, backup]

and

[{bucket, bucket_name}, analytics], [manage]

More details in the comments to DOC-5285 and in the linked Functional Overview Doc.