[fw-upgrade] Create a new permission to launch upgrades

[nemesifier]

• create a new permission to launch single upgrades
• create a new permission to launch mass upgrades

It may not be necessary to create a new permission, maybe we can get away with the permissions of the models that already exist (UpgradeOperation and MassUpgradeOperation) but we need to verify this.

If we need to create the new permissions, ensure they are automatically added to the administrator group (see #15).