Option to change action types names

[vabatta]

Would be great to have an option to change the hardcoded type action name such as this one
https://github.com/danielr18/connected-next-router/blob/master/src/actions.ts#L11 .

[danielr18]

Hey @vabatta, would you be able to create a PR for this?

If the onLocationChanged function is modified, you can pass the action name from this line:

connected-next-router/src/ConnectedRouter.ts

Line 82 in 6445d39

store.dispatch(onLocationChanged(locationFromUrl(url, as), action))

The part that may be complicated are the types.