fix: prevent reporting derived type on mapping from source

[faddiv]

Prevent reporting derived type on mapping from source

Description

I saw this report, and it looked easy enough to fix. So here it is.
This prevents reporting if the source variable is a derived type of the argument type.

Fixes #2024

Checklist

• The existing code style is followed
• The commit message follows our guidelines
• Performed a self-review of my code
• Hard-to-understand areas of my code are commented
• The documentation is updated (as applicable)
• Unit tests are added/updated
• Integration tests are added/updated (as applicable, especially if feature/bug depends on roslyn or framework version in use)

[latonz]

Thank you for this contribution!

[latonz]

Rebase and we can get this merged 🥳 Thanks for your efforts!

[EnesEfeTokta]

Your arrangements are really beautiful.

[faddiv]

Hi @latonz ,
This can be merged.