Summary:
We have started to support backing up and restoring global role objects

Backup Changes:
At backup time, have a field to backup global roles - pass a flag to useRoles to tell it to backup the roles
- Off by default

Restore Changes:
If roles were not backed up
- When trying to restore do not show "Restore Gloabl roles"

If roles were backedup in the first place
- Show option to "Restore Global roles" and have it Off by default
- if it turned ON, then show one more field "Fail restore if role already exists in target database"
    - Default will be false
    - If turned on, we need to pass useRoles and errorIfRoleExists to true in the restore API

Test Plan:
Please refer to the video
{F406077}

Reviewers: jmak, kkannan, dshubin

Reviewed By: jmak, dshubin

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D47655