Setting default values for weaviate server

[avirlrma]

partly fixes #2656

Changes

1. Setting default value for PERSISTENCE_DATA_PATH to ./data if not set in config and as env var.
2. Setting default value for AUTHENTICATION to Anonymous access enabled = true if not set in config and as env var.
3. Setting default value for QUERY_DEFAULTS_LIMIT to 10 if not set in config and as env var.
4. Add unit tests for these^.

Review checklist

• Documentation has been updated, if necessary. Link to changed documentation:
• Chaos pipeline run or not necessary. Link to pipeline:
• All new code is covered by tests where it is reasonable.
• Performance tests have been run or not necessary.

[weaviate-git-bot]

To avoid any confusion in the future about your contribution to Weaviate, we work with a Contributor License Agreement. If you agree, you can simply add a comment to this PR that you agree with the CLA so that we can merge.

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[sonarcloud]

Quality Gate failed

Failed conditions

15.9% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud

[reyreaud-l]

LGTM. Approved the CI tests run. Waiting to see their results.

[etiennedi]

Hey @avirlrma,

Thank you very much for your contribution. This should surely make it much easier to run Weaviate without any parameters!

Could you indicate (through a comment) that you accept the CLA? (See 🤖 comment above). Then we can merge.

[avirlrma]

I agree with the CLA.

[avirlrma]

Thanks for the review @reyreaud-l !

[parkerduckworth]

Thanks for the contribution @avirlrma!