Simplify naming #4

The idea of reusing the "stone" from the name was clever, but it has some drawbacks.

It doesn't fit in with NodeCore's generally purely concatenative naming scheme, where adjectives are prepended to general names for things.
It would make translations (or just general understanding) more difficult for non-native speakers.
It's a little weird separating certain words, like tarstone and cloudstone, because "tar" and "cloud" appearing on their own now seem to imply that that material is somehow used in the composition of the go stones.

Having all of the stones have "go" in their name also reinforces that these pieces are meant to be part of a logical set, used together, and are meant to be used for the game of go (in case somebody sees one in isolation and doesn't know what it's
from).

It also makes it easier to just search for "go" in szutil_givemenu and find all the go stones; searching for "stone" yields too many results.

I came up with a compromise solution.