Alter resource enum class name for argument parsing error messages

[priitlatt]

In case invalid value is passed to CLI argument which maps to enumeration, then the error message which is displayed to users does not look pretty as it contains the literal class name of the enumeration such as

$ app-store-connect builds submit-to-app-store --release-type 'invalid release type'
...
app-store-connect builds submit-to-app-store: error: argument --release-type: invalid ReleaseType value: 'invalid release type'

With the changes introduced here, the error above will look like

app-store-connect builds submit-to-app-store: error: argument --release-type: invalid release type value: 'invalid release type'