build: make configure.py compatible with python 3

This patch replaces the following

1. Usage of filter with None to remove falsy items.
2. Usage of map to create lists. (Replaced with List comprehensions).
3. Dictionary's iteritems which is removed in Python 3.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

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@nodejs/python @cclauss