Tag alias: black_&_white -> black_and_white

black_&_white -> black_and_white

Reason: Eliminate ampersand sign

forum #66645. i think before the alias pushes through, we must in a way decide the fate of black & white or a better tag name as 'opposition of b & w' against black and white (monochrome) since they appear to be 2 different ideas.

We could try either light_and_dark, or black_and_white_(theme).

As mentioned in the forum linked above, I think that black_vs_white is a good alternative.