Add command to delete saved wallet config

[tvpeter]

Describe the enhancement

The wallet config command stores the configuration information for a wallet in the cargo.toml file which is then reused on all subsequent wallet operations. However, there is no way to remove/delete a wallet configuration even when the wallet may no longer be needed.

Adding a command to delete a saved wallet configuration will help in reducing the number of redundant wallets configurations and improve the amount of data saved in the config file.

Use case

• This will allow users to clean up the wallet config file and remove redundant wallet configs.