text: Title: Json definition in core.remote action command
  Body: ## SUMMARY
  
  I need to insert a workflow parameter inside a Json definition for my action. 
  The first problem is that I can't even run the command with a Json definition in it (withou the parameter in the Json).
  ```
  input:
    - parameter
  
  tasks:
    run:
      action: core.remote
      input:
        cmd: command --json= '{"key1": "someValeu", "key": "secondValue" }'
  ```
  
  This results in the error:
  ```
  result: 
    errors:
    - message: "mapping values are not allowed here
    in "<unicode string>", line 16, column 78:
       ... command --json= '{ "key1": "someValeu", "key2": "secondValue" } 
                                    ^"
  ```
  
  The second problem is, assuming I can resolve the first one, as far as I saw in the examples and tested,  `<% ctx().parameter %>` cannot be used inside single quotes, it only works when used inside double quotes. But the Json only works if I define it using single quotes. In the end I would like to have the workflow:
  ```
  input:
    - parameter
  
  tasks:
    run:
      action: core.remote
      input:
        cmd: command --json= '{"key1": "someValeu", "key2": <% ctx().parameter %> }'
  ```
   
  
  ### STACKSTORM VERSION
  
  st2 3.4dev (c422f0029), on Python 3.6.9
  
  ##### OS, environment, install method
  
  Running on Kubenetes on k3os system. Deployed using stackstorm-ha
  
  ## Expected Results
  
  Is there a way to get around these problems?
  