Socketio metadata

[rgstephens]

Proposed changes:

• Adds metadata to the socket.io channel as requested in #11087

Status (please check what you already did):

• [ ] added some tests for the functionality
• [x] updated the documentation
• [x] updated the changelog (please check changelog for instructions)
• [x] reformat files using black (please check Readme for instructions)

[ancalita]

@rgstephens Following up on this if you'd want a 2nd review from me?

[rgstephens]

yes, thanks for the reminder

[rgstephens]

Before I give the final approval, asked a clarifying question on a docs sentence. Also please add a unit test if possible, that the metadata gets added to the UserMessage object.

Have not done unit tests before in Python so this make take me a while. Might be best to withdraw this PR rather than waiting on me to do this.

[ancalita]

Before I give the final approval, asked a clarifying question on a docs sentence. Also please add a unit test if possible, that the metadata gets added to the UserMessage object.

Have not done unit tests before in Python so this make take me a while. Might be best to withdraw this PR rather than waiting on me to do this.

As you prefer!

[ancalita]

@rgstephens Have you rebased recently? I just tried to review but see over 200 commits in this PR, might be easier to recreate PR targeting 3.2.x and close this one, we are actually planning a micro by the end of this week, latest early next week. I am available to give a fast review too 👍🏻

[rgstephens]

Closing. Rebased to 3.2.x and replaced by PR #11435