Handle normalization of pypi names in renaming

[analog-cbarber]

Pypi package names allow use of the characters ., _, and - but consider them to be equivalent. This is not true in conda (although in practice we don't expect to see package names that differ only in these characters in conda either).

The rename support code currently just considers the exact input name. Instead we should normalize the original
dependency name to canonicalize . and _ as -. This appears to be the standard used by a number of tools
and all of the existing stdrename entries have input names with dash.

We should also make sure to use case-insensitive lookup as well.