ActionCable: add id option to redis adapter config

[got2be]

Summary

Add id option to Redis adapter so now you can distinguish ActionCable's Redis connections among others. Also, you can set custom id in options.
Can be useful for debugging when a single Redis instance is used by multiple gems or applications.

Before:

$ redis-cli client list
id=669 addr=127.0.0.1:46442 fd=8 name= age=18 ...

After:

$ redis-cli client list
id=673 addr=127.0.0.1:46516 fd=8 name=ActionCable-PID-19413 age=2 ...

[rails-bot]

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