Fix #2446, clarify startup token count message

[sylvesterkaczmarek]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement.

Describe the contribution

Fix #2446.

Clarify the malformed startup-script diagnostic so the reported value is explicitly identified as NumTokens and the required minimum is stated.

The parser rejects entries with fewer than eight tokens. The previous message printed only the raw count, which could be mistaken for a startup-file entry or line number.

Testing performed

1. Added regression coverage for the existing zero-token error path.
2. The test verifies that the diagnostic contains NumTokens = 0, expected at least 8.
3. NASA Format Check passed.
4. NASA Static Analysis passed.
5. NASA Code Coverage Analysis passed.
6. NASA Code Coverage Analysis with EDS enabled passed.
7. NASA MCDC Analysis passed.
8. NASA Functional Test passed.
9. NASA Functional Test with EDS enabled passed.
10. NASA cFS Documentation and Guides passed.
11. NASA CodeQL Analysis passed.

Expected behavior changes

• API Change: none.
• Behavior Change: malformed startup-script entries with fewer than eight tokens produce a clearer diagnostic.
• Startup parsing and error-return behavior are unchanged.

System(s) tested on

• Repository baseline: cFE dev.
• Validation: NASA GitHub Actions workflows listed above.

Additional context

The branch is one commit ahead of dev, zero commits behind, and changes only the ES diagnostic plus its regression assertion.

Third party code

None.

Contributor Info - All information REQUIRED for consideration of pull request

Sylvester Kaczmarek, Personal