Move small hardhat tasks out of hardhat config for contracts-bedrock

[smartcontracts]

contracts-bedrock contains two hardhat tasks that should be in their own files inside of the /tasks folder instead. Simple issue for a first time contributor! Just move each of these tasks into their own task files (accounts.ts and solidity.ts) and then import these task files in the index.ts file.

Should be pretty straight forward but let me know if you have any questions!