Adding configuration files should load new accounts automatically without restarting EthSigner

[usmansaleem]

Expected Behavior: After adding toml configuration files in the config folder, the new accounts should be visible to eth_accounts and eth_signTransaction calls. https://docs.ethsigner.consensys.net/en/stable/HowTo/Transactions/Make-Transactions/

Current Behavior: eth_accounts call correctly reports the accounts available to EthSigner. eth_signTrasnaction call however, fails when new account is specified in from field.

Version observed: 21.3.2