Consider doing BLS ops is a worker thread

[dapplion]

BLS ops are currently very expensive. Research if it's worth it to offload some ops to a worker thread.
Pros:

• BLS is currently synchronous, so it can block and delay time-sensitive operations
• Consider validating deposits beforehand in group and storing the result to be consumed by the state transition.
  Cons:
• State transition function would have to become async.
• With native bindings, the improvements might be enough.

[wemeetagain]

A few more thoughts:

• Offloading bls to a worker may be useful when we're doing batch verification too
• If we prevalidate deposits, we won't need to make state transition function async, we will likely run batch verification as a pre-state transition step.
• Not all bls ops need to be worker-ized

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[dapplion]

unstale

[dapplion]

We have to wait to safely thread BLST supranational/blst#64 (comment)

However it would be valuable to start prototyping with WASM

[dapplion]

Implemented in #2328