[BEAM-7389] Created elementwise for consistency with docs

[davidcavazos]

No logic changes, only filename and region tag changes.

Changing some python filenames to match the docs filenames for consistency.

Will delete the old files as the docs get updated.

R: @aaltay

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Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---		---	---
Java
Python		---			---	---
XLang	---	---	---		---	---	---

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website
Non-portable
Portable	---		---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

[aaltay]

Could you update the docs, and delete obsolete files all in a single change?

[davidcavazos]

Yes, will do. Thanks!

[davidcavazos]

Updated docs and obsolete files deleted in #9692, but they won't render correctly until this one is merged.

[davidcavazos]

As per this plan, I will be moving code files from element-wise to elementwise for consistency.

[aaltay]

Is this ready to review?

[davidcavazos]

It is now ready for review.

No changes to logic

I did take the time to normalize all the code files to use relative imports as well as moving the asserts to check_ functions for consistency in the test files. Other than that, there are no changes from the element_wise counterparts besides the small changes to make linter and all tests pass.

[aaltay]

I do not see any deleted files or doc changes. Am I missing something?

[davidcavazos]

That would break the staged versions and the notebooks would have to be generated in a second pass anyways. I'm doing that here #9692, that way we don't temporarily break things in the website.

[aaltay]

OK. Merged this, please do the clean up as soon as possible.