Add reducers for generated components

[jayantbh]

Is your feature request related to a problem? Please describe.
Components can not be created with any redux state using the CLI.

Describe the solution you'd like
Add a reducer file to the generated component, supported using a flag, and defaults.

Describe alternatives you've considered
No alternatives considered as of now.

Additional context
This will resolve a minor inconvenience of having to manually connect a component to redux.
It would be great if Terrace could also use JS code parsing and generation add the reducer for this, and other views to the root reducer automatically, but that's a different task altogether.