errors: add ERR_REDIRECT
This error is meant to be returned if a resource is requested that does
not exist under the requested name anymore but was moved to a different
resource.
server: add error presenter to make context cancellation semantic
auth: ensure semantic errors are bubbled up to user properly
auth: add error code on unauthorized request response
errors: Fix ErrUnsupported error code
errors.Field: return the error
errors: add ERR_UNSUPPORTED
errors: new module for common GQL errors
This package provides a means of creating GraphQL-aware errors and
a location for common error codes.