ResolveScopeList converts a scope list from a token request's `scope` parameter into a list of standard access objects.

ResolveScopeSpecifiers converts a list of scope specifiers from a token request's `scope` query parameters into a list of standard access objects.

ToScopeList converts a list of access to a scope list string.

ErrorBadTokenOption is returned when a token parameter is invalid.

ErrorMissingRequiredField is returned when a required form field is missing.

ErrorUnsupportedValue is returned when a form field has an unsupported value.

TokenIssuer represents an issuer capable of generating JWT tokens.