Python: (Astra DB) Explicit projection when reading from Astra DB

[hemidactylus]

Motivation and Context

In view of upcoming changes in the Astra DB Data API, this PR explicitly sets a projection every time a find command is executed, in order to ensure all necessary fields of the document are returned by the API.

Description

Added an else branch in the astra_client.py to ensure there always is a "projection" field in the body for the find command. This ensures that $vector is returned by the API even in case of Astra DB rolling out an exclude-it-by-default policy in the future.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[markwallace-microsoft]

Python 3.10 Test Coverage Report •

File	Stmts	Miss	Cover	Missing
TOTAL	6098	881	86%

report-only-changed-files is enabled. No files were changed during this commit :)

Python 3.10 Unit Test Overview

Tests	Skipped	Failures	Errors	Time
1374	1 💤	0 ❌	0 🔥	17.006s ⏱️