Python package name comparisons should use PEP 503 normalization

[chennes]

When listing the pip-installed packages in the dependencies window, the analysis of dependencies should use PEP 503 normalization (case insensitive, and dash, underscore, and dot all treated as equal).

[BackwardEcho]

In relation to the Telemetry addon v1.0.2 needing a "typing-extensions" dependency, which shows up as "typing_extensions" in the Addon Manager and not calling out that it is a dependency for Telemetry.

[BackwardEcho]

Was asked to test and this is me posting the results here (an hour later).