Fix: Prevent redefinition of imported types in model validation (#871)

[yashsaraswat2004]

Closes #871

Changes

• Added validation logic to check for name conflicts between local declarations and imported types.
• Updated uniqueNames set to include imported types and prevent redefinition.

Flags

• Ensure validation does not impact performance significantly.
• Review the handling of imported namespaces across different modules.

Screenshots or Video

N/A

Related Issues

• Issue Redefining an imported type is allowed  #871

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests.
• Commits messages follow AP format.
• Extend the documentation, if necessary.
• Merging to main from fork:Yash_fixing-bugs.

[dselman]

You've reformatted the files making it very hard to review your changes. Can you please resubmit without reformatting?

[yashsaraswat2004]

I'm really sorry to change the formatting of code. I will sure resubmit it without reformatting.

[dselman]

Impossible to review due to amount of whitespace changes.