Minor Description
The implementation of several modules that support 2FA/MFA has resulted in some scenarios where "GuacamoleInsufficientCredentialsException" exceptions are override by "GuacamoleInvalidCredentialsException" exceptions. Due to the way the AuthenticationService class currently handles those exceptions, there is no precedence - the first exception thrown is the one that is returned. This behavior should be changed such that GuacamoleInsufficientCredentialsException takes precedence over GuacamoleInvalidCredentialsException so that modules requesting additional credentials are not overriden or failed by modules that completely fail authentication. This will resolve some issues with the order of stacked modules mattering for whether authentication fails or prompts for additional credentials.