Comment 1 for bug 1638598

Currently the UpdateParametersAction only updates the mistral environment with updated values. This is quite insufficient because value needs to get validated by heat before it is saved.

If value which fails validation gets saved in mistral environment, it is no more possible to successfully get parameters which means UI is not able to fix the situation without resetting the mistral environment.

Proposed flow:
1. Receive a list of parameter names and values to update
2. Run GetParametersAction including those parameters (runs heat-validate)
3. In case of success, return response from GetParametersAction
4. In case of failure, return error response from GetParamertersAction (If heat provides the data, it would be nice if response included parameter errors in format
{ Parameter1: 'error message',
  Parameter2: 'another error }