Allow more than one action to be executed in existing operations

[danielonsecurity]

For example:

(Grep
  :regex "TWO_FA_REQUIRED"
  :action
  (NextStage "multi_factor")
  :otherwise
  (NextStage "get_access_token"))

Instead of having only one allowed action like the NextStage here, it would be useful to add more than one, maybe in a list.