"connect_to" support for "pillar" type

[WenXin20]

Currently, the "pillar" type does not support the "connect_to" option, which could be useful for my chiseled stone brick texture to be able to connect to the infested chiseled stone brick, because if a silverfish infests a chiseled stone brick, it would give away it's position as the block would change its texture instead of connecting. This would be nice to see someday.