fix: check ast node on later renamers for cli v2 updater

[metrizable]

Issue #, if available:
Fixes #1847

Description of changes:

check for None on node for renamers following the serde renamers for the cli v2 updater

Testing done:

new test included:

❯ tox --parallel 3 -- -rfE --disable-warnings tests/unit
✔ OK black-format in 7.632 seconds
✔ OK flake8 in 23.871 seconds
✔ OK twine in 17.505 seconds
✔ OK pylint in 32.506 seconds
✔ OK doc8 in 19.725 seconds
✔ OK sphinx in 32.056 seconds
✔ OK py37 in 4 minutes, 18.556 seconds
✔ OK py36 in 4 minutes, 39.279 seconds
✔ OK py38 in 4 minutes, 26.307 seconds

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• Commit ID: 0e8248c
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