[9.x] Pusher authorized connections

[rennokki]

Before merging:

• [9.x] User authentication for Pusher framework#42531
• [9.x] Fixed grouping for user authorization framework#42664
• User Authentication echo#340

[rennokki]

@taylorotwell

[taylorotwell]

I don't see any such method channelAuthorizationRoutes in the framework?

[rennokki]

@taylorotwell Missed that by accident.

[taylorotwell]

We probably need to be more specific about where exactly to call Echo.signin()

[driesvints]

@rennokki did you have time for this yet?

[rennokki]

@taylorotwell Fixed that.

[taylorotwell]

Honestly I'm going to table this documentation for now. It's not a super in-demand feature of Echo. I may revisit this to give it proper documentation in the future.