Add the ability to set persistent locks on a configuration

[abtreece]

Would like the ability to lock/unlock a configuration from further changes.

[brikis98]

Ah, neat idea. It should be fairly easy to add a terragrunt lock command.

Out of curiosity, what is your use case?

[abtreece]

We are (currently) splitting up the configurations for the network and compute components and would probably consider locking the underlying infrastructure that compute configurations are built on top of.

[brikis98]

Is anyone interested in submitting a PR for this? All the code for the locking mechanism is already in place, so all you'd need to do is expose a new command in the CLI.