Streaming: Rework websocket server initialisation & authentication code

[ThisIsMissEm]

This moves us away from the deprecated verifyClient mechanism, to using a custom 'upgrade' event handler as recommended by the author of the ws module.

In the future, we should probably move towards using a custom WebSocket subclass to add in additional methods and data directly to the WebSocket instance, by passing the WebSocket option, which would give a cleaner abstraction for the logger and other data we may want to attach to the websocket, such as isAlive — you can see what that'll look like in this branch: https://github.com/mastodon/mastodon/compare/main...ThisIsMissEm:mastodon:experimental/custom-eventsource-and-websocket-classes?expand=1

[ClearlyClaire]

Looks fine overall, but I'd prefer keeping the requestId stuff for now, especially since it's still used in places…

[ThisIsMissEm]

Looks fine overall, but I'd prefer keeping the requestId stuff for now, especially since it's still used in places…

I hear you, but there's a reason this was originally all done in the logging change, because these are all strongly related, imo.

[ClearlyClaire]

Looks fine overall, but I'd prefer keeping the requestId stuff for now, especially since it's still used in places…

I hear you, but there's a reason this was originally all done in the logging change, because these are all strongly related, imo.

I still don't understand why it's part of this commit and not the other one… I don't understand what requires the requestId definition to be removed from this commit.

[ThisIsMissEm]

@ClearlyClaire just to clarify, are you saying this won't be merged as long as the request ID changes are in here? And that you want me to spend 30-60 minutes to pick those out just to do them in another already opened pull request that this was split from at Renauld's request?

Because that's going to delay being able to move forwards with this until I have the time & energy to do those additional changes.

[ClearlyClaire]

I prefer if we don't add an unnecessary regression, however small and temporary. I can try and take this PR over if you prefer.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (557c27e) 84.77% compared to head (bc5931b) 84.84%.
Report is 56 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #28631      +/-   ##
==========================================
+ Coverage   84.77%   84.84%   +0.06%     
==========================================
  Files        1039     1038       -1     
  Lines       28162    28152      -10     
  Branches     4541     4534       -7     
==========================================
+ Hits        23875    23886      +11     
+ Misses       3129     3103      -26     
- Partials     1158     1163       +5     

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[ThisIsMissEm]

@ClearlyClaire have finished rebasing this, and also #27828 — hopefully these are both good to go now.