feat: Piscina implementation for bulk-lssuance

[tipusinghaw]

trafficstars

piscina Implementation for bulk-issuance using workers

[tipusinghaw]

It's not possible to pass function or inject dependency to the worker file docs: https://stackoverflow.com/questions/12303566/node-js-sending-an-object-with-function-definitions-to-worker-thread/12303840#12303840

[pranalidhanavade]

Closing as per @tipusinghaw 's comment above