EnvType is an enum that represents the environment type.
EnvType is derived from the strum crate, which provides the ability to convert the string to the enum.
AsEnvTypeStr is a trait that covert some type to a string with Key Type, which is the environment type.
This trait can extend the existing configuration struct to get the environment type.
AsEnvTypeStr is a trait that covert some type to a string, which is the environment type.
This trait can extend the existing configuration struct to get the environment type.