rename mssql_ret2 to mssql and snowflake_ret to snowflake

[erdincka]

Provide a clear and concise description of the content changes you're proposing. List all the changes you are making
to the content.

• Updated section Superset tutorial with valid data source names.
• Removed outdated information from 01-data-source-connectivity-and-exploration.ipynb where it suggests to change Enable Transparent Cache option which is not available for MSSQL data source in UA 1.4.
• Updated demos/rag-demos/question-answering-gpu/documents/EzUA.json file to reflect these changes.

Closes #185

Checklist:

• I have checked that my enhancements are not duplicates of existing content changes or additions.
• I have tested the changes in a working environment to ensure they function as intended.
• I have followed the style guide
  outlined in the contribution guidelines.

Reviewer's Tasks (for maintainers reviewing this PR):

• Verify that the tutorial functions correctly in a live environment.
• Verify that the updated content aligns with the style guide
  in the contribution guidelines.
• Check for consistency, grammar, and clarity throughout the updated content.
• Check that the related GitHub issue is up-to-date.