fixes #6113 - add lifecycle environment tab to smart proxy / capsule form
Refs #6113 - use dynflow tasks to modify capsule lifecycle env

 * Disable lifecycle environment modifications for default capsule
 * Extends foreman's smart_proxies controller to support dynflow actions
     on update
Merge pull request #4323 from jlsherrill/capsule

fixes #6113 - add lifecycle environment tab to smart proxy / capsule