Add "Lock to Contract" as a Parameter in Parameter Maintenance

Currently, if we need to lock all of the users in a large account to a contract, we can mass assign the entire account to the contract in Parameter Maintenance, but we have to manually lock each user to it one by one in Customer Maintenance. It would be helpful to be able to lock everyone at once in Parameter Maintenance as well. "Lock to Catalog" is an option in there, but not "Lock to Contract."