SNOW-1903631 Add more explicit error message when username or password is missing id DataSource

[fabiencelier]

Overview

SNOW-1903631

Pre-review self checklist

• PR branch is updated with all the changes from master branch
• The code is correctly formatted (run mvn -P check-style validate)
• New public API is not unnecessary exposed (run mvn verify and inspect target/japicmp/japicmp.html)
• The pull request name is prefixed with SNOW-XXXX:
• Code is in compliance with internal logging requirements

External contributors - please answer these questions before submitting a pull request. Thanks!

1. What GitHub issue is this PR addressing? Make sure that there is an accompanying issue to your PR.

   Issue: SNOW-1903631: Unclear error message when no password set in DataSource #2055

2. Fill out the following pre-review checklist:

   • I am adding a new automated test(s) to verify correctness of my new code
   • I am adding new logging messages
   • I am modifying authorization mechanisms
   • I am adding new credentials
   • I am modifying OCSP code
   • I am adding a new dependency or upgrading an existing one
   • I am adding new public/protected component not marked with @SnowflakeJdbcInternalApi (note that public/protected methods/fields in classes marked with this annotation are already internal)

3. Please describe how your code solves the related issue.

Simply check the parameter (username and password) before putting them into the ConcurrentHashMap so we get a clearer error message instead of a NullPointerException.

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[fabiencelier]

I have read the CLA Document and I hereby sign the CLA

[sfc-gh-dprzybysz]

Thank you @fabiencelier for the contribution