[bulk] Multicolored Polka Dots

create implication multicolored_polka_dots -> polka_dot

Link to request

Subset.
A bit iffy, because it seems that the request is deleted if I compare the requests from EB and ricetaffy here:
EB updated the BUr afterwards and deleted it(?) but the implication would make sense...@EB ?

@EB

Request already exists in forum #122723.

The bulk update request #974 has been rejected.

I accidentally submitted it as an alias first and rejected that one. But I had forgotten about the big multicolored BUR, so looks like I had already messed up thinking I needed to submit it in the first place...