ocean_bottom alias

BUR #18515 has been approved by @nonamethanks.

create alias ocean_bottom -> seafloor
create alias ocean_floor -> seafloor

Ocean floor has 15 million Google results, seabed has 32 million, and seafloor has just shy of 40 million. In comparison, "ocean bottom" has less than 2 million. We should go with the most widespread term.

Had to remove the seabed -> seafloor line because seabed is apparently a copyright tag (for whatever reason).

BUR #18518 has been approved by @nonamethanks.

rename seabed -> seabed_(visual_novel)

Ambiguous

The bulk update request #18518 (forum #248486) has been approved by @nonamethanks.

The bulk update request #18515 (forum #248482) has been approved by @nonamethanks.