Add messageSizeLargerErrFmt error to errors catalog

[pracucci]

The messageSizeLargerErrFmt error should be added to the errors catalog. This error is returned when the incoming push request size is bigger than the allowed limit:

mimir/pkg/util/http.go

Lines 175 to 183 in 065f6d6

	func decompressRequest(dst []byte, reader io.Reader, expectedSize, maxSize int, compression CompressionType, sp opentracing.Span) (body []byte, err error) {
	defer func() {
	if err != nil && len(body) > maxSize {
	err = fmt.Errorf(messageSizeLargerErrFmt, len(body), maxSize)
	}
	}()
	if expectedSize > maxSize {
	return nil, fmt.Errorf(messageSizeLargerErrFmt, expectedSize, maxSize)
	}

The related config option to control the limit is defined here:

mimir/pkg/distributor/distributor.go

Line 175 in 065f6d6

f.IntVar(&cfg.MaxRecvMsgSize, "distributor.max-recv-msg-size", 100<<20, "remote_write API max receive message size (bytes).")

We should take the opportunity to improve the config option description too.