Ability to choose if new methods/metrics should be enabled/disabled for existing/new plans with Toolbox

Current behavior
When a method is added to the definition of a service in the Admin Portal, it is enabled for all application plans

e.g of a real use case
We have 12 plans already and today the guy added 5 new methods to existing 423 mapping rules in PROD. So he had to re-visit all the 12 previously created plans and manually disable the new methods. Then come to the new 02 application plans and disable 846 (423 x 2) methods manually.

Request
Ability to add a new method indicating if you want it enabled or disabled by default in existing plans.

Proposed solution
Proposing to make this possible using the toolbox CLI until it gets implemented in he system UI. The way it'd work is creating metrics with a limit of 0 for eternity for disabled status.

Equivalent issue in system https://issues.jboss.org/browse/THREESCALE-1248