alias x_kneehighs -> x_socks

BUR #11979 has been approved by @evazion.

create alias striped_kneehighs -> striped_socks
create alias vertical-striped_kneehighs -> vertical-striped_socks

To go inline with other kneehighs -> socks alias

The bulk update request #11979 (forum #220101) has been approved by @evazion.