[WIP] Prepare for a new release

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original issue description:

Following this rules:

• Use branch fix_last_real
• Do not modify source code, you can modify and delete tests.

I have done a lot changes to /src/mpzsql , because of that some test may fail.

Create a status of all test, delete the ones that are not needed anymore, and add more to improve coverability.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Prepare for a new release</issue_title>
<issue_description>Following this rules:

• Use branch fix_last_real
• Do not modify source code, you can modify and delete tests.

I have done a lot changes to /src/mpzsql , because of that some test may fail.

Create a status of all test, delete the ones that are not needed anymore, and add more to improve coverability.

</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #66

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[MiguelElGallo]

no