alias growing_hair -> hair_growth

BUR #55321 has been approved by @nonamethanks.

create alias growing_hair -> hair_growth

to be consistent with muscle growth, height growth, etc.

Terrible idea that just entered my brain, but "hair growth" could also be misunderstood to be for cancerous growths with hair in it... Maybe not a concern unless we get some really horrible horror / guro posts.

The bulk update request #55321 (forum #420229) has been approved by @nonamethanks.