* json > nim-serde bump
Should wait until serde is integrated into nim-ethers before making these changes as there will be less import exceptions required.
* bump nim-serde
* change func to proc due to chronicles side effects
* import serde into utils/json, use as proxy
import nim-serde into utils/json and use utils/json as a proxy for serde functions, including overloading `%` and `fromJson` for application types.
* update tests to use serde
* bump serde to latest
* remove testjson -- no longer needed
* bump serde in nimble
* updates to reconcile rebase with master
* rework backend to instantiate key at initialization
* add groth16 convertes for solidity
* prover taks num samples on construction
* add zkey file
* rework helpers
* rename types
* update tests
* reworked test helpers
* rename types
* rework test
* test all slots artifacts
* bump to latest version
Eric
Dmitriy Ryajov