Spin off English functions and data, incl. test files

[ChanceNCounter]

(credit @Tony763 for lighting a fire under me)

We should finish isolating that which is English-specific from that which is merely "the default section." When contributors go to localize functions and tests, it's common to start with some copy/pasting from a similar language, or from English. However, because the English files and the top-level modules used to be the same files, copying and pasting from English can bring along logic that isn't exactly English-specific.

This definitely still applies to the test crawlers. I'm not sure what else might still be hiding.