YUV/YCrCb conversions rewritten to wide intrinsics (#13649)

* YUV: minors

* YUV42x conversions template-merged

* more template-merged YUV42x conversions; some NEON code removed

* rgb2yuv<float> vectorized

* yuv2rgb<float> vectorized

* memcpy removed

* Yuv2RGB<ushort> vectorized

* unused code removed

* rgb2yuv<ushort> vectorized

* rgb2yuv<uchar> vectorized

* v_pack_u used (up to +30% perf)

* yuv2rgb<uchar> vectorized

* fixed compilation