Utilize worker threads

[Siegrift]

@bdrhn9 had a good idea that by spawning multiple workers we might leverage the additional CPU cores. This would also reduce the overhead of the "main" loop that currently does everything.

From the quick look there don't seem to be any downsides to implementing this.

[Siegrift]

A big downside to this is that workers run in isolation. So for example, given we have 2 cores - we can't just operate an Airseeker on 10 chains and 5 per CPU. We would also need to have separate state and fetch Signed data for every worker. It's basically similar to having just a single Airseeker deployed.

What this could be used for is Signed data validation, because that is CPU heavy. And unfortunately, I don't see any other CPU intensive operations we could offload to a separate thread.

Related discussion: https://api3workspace.slack.com/archives/C05TQPT7PNJ/p1714514780191139

[Siegrift]

This was resolved by accident (by mentioning this issue in the #288 PR).

[Siegrift]

Agreed on call to whitelist signed data URLs from the config as suggestion in the original Slack thread.