We need to allow overruns during the async multi-broker context spawning
init bc some backends might take longer then others to setup (eg.
binance vs. kucoin) and result in some context (stream) being overrun by
the time we get to the `.open_stream()` phase. Ideally, we can maybe
adjust the concurrent setup to be more of a task-per-provider style to
avoid this in the future - which would also in theory result in
more-immediate per-provider setup in terms showing ready feeds asap.
Also, does a bunch of renaming from fqsn -> fqme and drops the lower
casing of input symbols instead expecting the caller to know what the
data backend it's requesting is going to be able to handle in terms of
symbology.