Improve ResolutionImpossible error message clarity

[nishtha-agarwal-211]

What does this PR do?

Improves the ResolutionImpossible error message by making it clearer and more actionable for users encountering dependency resolution conflicts.

What changed?

• Replaced Unicode bullet points with ASCII hyphens for better terminal compatibility
• Added clearer, step-by-step guidance on how users can resolve dependency conflicts
• Preserved existing logging and error structure

Why is this change useful?

This improves the developer experience by:

• Making the error message easier to read across different terminals
• Providing concrete next steps instead of generic guidance

Related issue / discussion

N/A

[notatallshaw]

Thanks for your PR, I'm pretty good with this change but I'll do a more detailed review of the language when I get a moment.

Currently CI checks are failing due too long line lengths, you will need to fix this, you can run CI checks locally to assist if you want: https://pip.pypa.io/en/stable/development/getting-started/#running-linters

[nishtha-agarwal-211]

Thanks for the review! I’ve fixed the line-length issues and all CI checks are now passing. Happy to make any further wording adjustments if needed.