Clear up region-specific code.

[relaera]

This reduces network, CPU, and memory overhead by reducing the data requested, transformed, and processed by two-thirds. Some language referencing "region" still remains, but the regions have been condensed to key off of "any".

As this changes keying, you may want to defer this change until v4, but that's up to you.
The change also fixes the api.md page to update the description of regions, and update the example output.

This commit also removes the unused region_helper_v2 function

[Fuyukai]

I'm probably going to merge this manually to my new rewrite which is about 50% complete, and bump the version there, but thanks a lot for this.

[relaera]

For our needs, we needed to pare down processed data immediately, so I rekeyed and left V3, but I'm glad you can use this