Add "skip" option to subscription hook

[brianjd]

Description

Add skip option to 'useSubscription' hook.

Suggested implementation

Add option, default to false. If true, early return before creating observable.

[brianjd]

cc: @simoneb

Is there a discussion to be had or just proceed with PR?

[simoneb]

feel free to create a PR if you know already how to implement your proposal!