feat: worker thread implementation for issuance service

[tipusinghaw]

trafficstars

• [x] Implement worker thread in agent for time intensive method

[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