fix: add docs snippets; fix open api issues

[szuperaz]

https://linear.app/stream/issue/REACT-1069/migrate-client-side-chat-qa-tests-to-v10-of-stream-chat-js

Migrates the docs-snippets test project from v9 -> v10. It contains all docs and platfrom stream-chat-js docs snippets we have. Relevant docs branch: https://github.com/GetStream/getstream.io/pull/683 (will be kept in sync with getstream.io/main until we're ready to release stream-chat-js).

Most changes are to docs-snippet project, and src/gen, however, some client issues were found by the tests and those are fixed as well, so PR title is fix.

Fixed client issues

Most changes are type fixes, 1-2 behavioral; here are the most important ones:

• queryThreadsAndHydrate / getThreadAndHydrate now return the already-registered Thread through the new ThreadManager.resolveQueried. Before, they built a second instance that activate() and incoming events didn't reach. A registered thread that is out of date and not open gets refreshed from the query result.
• channel.sendEvent method expected the response Event type, instead of the request. So it expected fields like created_at, custom. Fixed it, this method now expects the event request type
• client.devToken() is back (I think this was mistakenly removed with other server-side stuff)

TODOs

Apart from the client changes in this PR, we have 3 small, pending todos to generator/open api spec. All tracked in the docs-todo file. The run also caught a bunch of smaller API behavior issues; since these issues are present on api v1 and v2 as well, they're not blocking us. I'll verify the findings and pass them to the backend team once I have the time.

[szuperaz]

This one threw me off at first, but I verified that, for ai_indicator.update events, the message_id and ai_state fields need to be wrapped in custom, but then when the backend broadcasts the event, it will read these fields from custom and add them to event.message_id and event.ai_state.