Swap to semantic version

[noah978]

Currently using packaging.version to compare versions found in AltSources and GitHub release tags. The AltSource API is designed to work explicitly with the semantic versioning protocol, so altparse should restrict valid versions to using that.

Here is the relevant PyPI and docs:

• https://pypi.org/project/semantic-version/
• https://python-semanticversion.readthedocs.io/en/latest/

[noah978]

There may be potential complications in this where users may have GitHub repos that don't follow semver, but the internal IPA being distributed does. However, it should be the responsibility of the IPA developer to appropriately distribute their app.