Fix distribution name normalization (PEP-0503)

[rominf]

Current logic in test_installed_modules does not properly handle
distributions with underscores. On my machine I get the following error
while running tests:

tests/integrations/modules/test_modules.py:60: in test_installed_modules
    assert installed_modules == pkg_resources_modules
E   AssertionError: assert {'aiven-clien...'22.2.0', ...} == {'aiven-clien...'22.2.0', ...}
E     Omitting 93 identical items, use -vv to show
E     Left contains 1 more item:
E     {'tomli_w': '1.0.0'}
E     Right contains 1 more item:
E     {'tomli-w': '1.0.0'}
E     Use -v to get more diff

This change fixes distribution name normalization by applying the code
from PEP-0503 (https://peps.python.org/pep-0503/#normalized-names).

[rominf]

I get the same error while building Fedora package on Fedora servers: https://kojipkgs.fedoraproject.org//work/tasks/659/101530659/build.log

=================================== FAILURES ===================================
____________________________ test_installed_modules ____________________________
tests/integrations/modules/test_modules.py:60: in test_installed_modules
    assert installed_modules == pkg_resources_modules
E   AssertionError: assert {'aiohttp': '... '3.5.0', ...} == {'aiohttp': '... '3.5.0', ...}
E     Omitting 113 identical items, use -vv to show
E     Left contains 1 more item:
E     {'tomli_w': '1.0.0'}
E     Right contains 1 more item:
E     {'tomli-w': '1.0.0'}
E     Use -v to get more diff

This prevents me from packaging newest version of python3-sentry-sdk for Fedora.

[sentrivana]

Hey @rominf, thanks a lot for fixing this! If the tests are green this LGTM.