Update release process for independent package versioning

[ni-jfitzger]

In order to support package version independence, our release process will need to change, as well as how we tag releases.

The tag naming changes will have implications for ReadTheDocs projects, as well as the LATEST_RELEASE file used by examples.rst.mako. ReadTheDocs stable version labels and maybe version labels in general expect semver tags and injecting a module name into the tag will affect its behavior (like whether it even adds the version).

See https://docs.readthedocs.io/en/stable/versions.html and https://docs.readthedocs.io/en/stable/automation-rules.html#how-automation-rules-work

[ni-jfitzger]

Possible changes: aeee08d
TODOs remaining from those changes:

• Further update build_release.py to allow specifying which packages to release.
• Update ReadTheDocs projects rules to deal with new Git tag naming scheme for releases.
• Do we need readthedocs configuration yamls?