This adds the governance token config to the `DeployConfig`.
The `name`, `symbol` and `_owner` can be set via new config options.
We must set these values to be `Optimism`, `OP` and the address
of the mint manager for the upgraded networks.

This change allows new networks to easily configure the gov token.
This is important so that other networks do not spin up a chain
that has a gov token that looks exactly the same as `OP`. This
will enable scammers.

In my opinion, we should also make the `MintManager` a predeploy
because it is the only L2 contract that we manage that is not
a predeploy.