fix(templates): Move tests in cookiecutters to project root to support pytest_plugins

[edgarrmondragon]

Closes #1377

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📚 Documentation preview 📚: https://meltano-sdk--1380.org.readthedocs.build/en/1380/

[codecov]

Codecov Report

Merging #1380 (89d4c29) into main (a304bb2) will not change coverage.
The diff coverage is n/a.

❗ Current head 89d4c29 differs from pull request most recent head 2113463. Consider uploading reports for the commit 2113463 to get more accurate results

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[edgarrmondragon]

@kgpayne I would appreciate your 👀 on this PR. This may be a blocker for new taps and targets created from the cookiecutter templates to start using the new testing framework immediately.

[kgpayne]

LGTM @edgarrmondragon 🚢 I did this in tap-snowflake but didn't clock that it might be a wider issue 🤦‍♂️ Once this merges, we should update the testing guide. IIRC the pytest error is quite clear, but still useful to document 🙂 Looks like there isn't an explicit migration guide, but I updated the testing docs with the new location.