add sample files for #21701

[chacha21]

add sample files for #21701

[chacha21]

10b and 14b samples are not rendered correctly by the Windows File Explorer or many other softwares, by lack of support.
When opened by ImageJ, they are correct

For information, they are produced by ImageMagick
(the interpolate and dither options are failed attempts to keep the exact same pixel values when converting depths)

convert pattern_8uc1.tif -resize 15x7! -interpolate nearest-neighbor -depth 10  +dither pattern_10uc1.tif
convert pattern_8uc3.tif -resize 15x7! -interpolate nearest-neighbor -depth 10  +dither pattern_10uc3.tif
convert pattern_8uc4.tif -resize 15x7! -interpolate nearest-neighbor -depth 10  +dither pattern_10uc4.tif
convert pattern_8uc1.tif -resize 15x7! -interpolate nearest-neighbor -depth 12  +dither pattern_12uc1.tif
convert pattern_8uc3.tif -resize 15x7! -interpolate nearest-neighbor -depth 12  +dither pattern_12uc3.tif
convert pattern_8uc4.tif -resize 15x7! -interpolate nearest-neighbor -depth 12  +dither pattern_12uc4.tif
convert pattern_8uc1.tif -resize 15x7! -interpolate nearest-neighbor -depth 14  +dither pattern_14uc1.tif
convert pattern_8uc3.tif -resize 15x7! -interpolate nearest-neighbor -depth 14  +dither pattern_14uc3.tif
convert pattern_8uc4.tif -resize 15x7! -interpolate nearest-neighbor -depth 14  +dither pattern_14uc4.tif
convert pattern_8uc1.tif -resize 15x7! -interpolate nearest-neighbor -depth 16  +dither pattern_16uc1.tif
convert pattern_8uc3.tif -resize 15x7! -interpolate nearest-neighbor -depth 16  +dither pattern_16uc3.tif
convert pattern_8uc4.tif -resize 15x7! -interpolate nearest-neighbor -depth 16  +dither pattern_16uc4.tif