Consider whether to grant a permanent approval to add Ethereum gauges to a particular account in the coordinator

[TomAFrench]

Currently the veBALDeploymentCoordinator adds an initial set of gauges and then revokes all rights to add more. In order to add more gauges the admin multisig would need to re-grant this permission to another address in future.

We should consider whether we want to just grant this permission to an address immediately and if so, which address?

See #1187 (comment)