The Vector128<byte> overload of SSSE3 Shuffle is missing

[fiigii]

We should add Vector128<byte> overload for SSSE3 Shuffle to keep consistent with other ISAs and avoid calling StaticCast.

        /// <summary>
        /// __m128i _mm_shuffle_epi8 (__m128i a, __m128i b)
        ///   PSHUFB xmm, xmm/m128
        /// </summary>
        public static Vector128<sbyte> Shuffle(Vector128<sbyte> value, Vector128<sbyte> mask) => Shuffle(value, mask);

[voinokin]

(Is also in #10385 item 5)

[fiigii]

@voinokin Thank you for pointing that out!