(feat) runtime: in _wait_until_alive upon start wait for client to have initialized too

[tobitege]

Short description of the problem this fixes or functionality that this introduces. This may be used for the CHANGELOG

EventStreamRuntime will wait for runtime client to be initialized once, for up to 10s.

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Give a summary of what the PR does, explaining any non-trivial design decisions

The runtime starts the client and should wait for its full initialization before resuming normal processing.
This will only be done once and only for up to 10 seconds so to not get stuck.

@xingyaoww Let me know what you think about this approach.

[xingyaoww]

LGTM!

"/alive" return success basically means runtime client is also initialized -- Based on my understanding, this PR should help with the logging before the runtime client is alive, right? (e.g., we get more info about the initialization process)

[tobitege]

LGTM!

"/alive" return success basically means runtime client is also initialized -- Based on my understanding, this PR should help with the logging before the runtime client is alive, right? (e.g., we get more info about the initialization process)

The container already gives you the alive signal before the client is initialized, that's why I thought this PR makes sense to avoid delayed "clashes" if the runtime would start with sending commands and the client still starting.