feat: mutex for searching transactions

[PhearZero]

Proposed Changes

• Add a Mutex to the chunked filter

This could be a Semaphore with known safe number of in-flight requests. For now I've made it a Mutex just to continue testing the library.

[robdmoore]

Assume this is to stop bulk requests being sent to indexer api in parallel?

To your point there is a balancing act here, might want to have a certain number in parallel to speed things up without DoSing the API?

[PhearZero]

Exactly, I had about a dozen accounts as filters and it was rate limiting. Reached for a Semaphore since it has been useful in this context.

There could be a better way to limit in-flight requests but the Semaphore could still be useful as a fail safe