Support publishing with static python dependency

[isc-shuliu]

See #698

When finished, this PR will support searching for python packages (in the Embedded Python runtime) and exporting all/selected python packages as .whl as part of the package or publish lifecycle phase.

TODO:

• investigate structure of .whl and best practices of generating .whl (along with .whl translative dependencies)
• determine a default path to place generated .whl files
• ensure relevant data is persisted when exported to XML installer
• add a resource processor for installing local .whl files
• integration tests for dummy .whl packages with dependencies
• when -export-deps 1 modifier is present, publish python dependencies as well