Improve dependency conflict error messages

[dinkelspiel]

Improved the error message for dependency resolution failures to more clearly
explain why the conflict occurs. Previously, the error message only listed the
names of the conflicting packages:

- mist
- server
- cors_builder

Now, the message provides more detailed descriptions:

- Package `app` requires `cors_builder` 1.0.0 <= v < 2.0.0
- Conflict with the `mist` package:
    - `cors_builder` requires `mist` version 1.0.0 <= v < 2.0.0
    - `app` requires `mist` version 3.0.0 <= v < 4.0.0

[giacomocavalieri]

Hello! This is being worked in #3640
Unfortunately it's blocked by an external issue with a dependency that doesn't allow us to display the version constraint nicely: pubgrub-rs/pubgrub#258 (comment)

The default to_string implementation was deemed confusing and that's why it was removed from the error message; so there's not much we can do until the pubgrub package resolves this

[dinkelspiel]

Of course i'm biased, but i'd still argue that it's good to merge this in the meantime. I had this issue today and it tells you next to nothing, I think it's better to merge this so it's there and gives information rather than having to wait for an external dependency to merge something so we can mitigate some poor soul having to search through each dependencies gleam.toml to find the issue.

[giacomocavalieri]

I agree with you, but I've already had this talk with Louis and he won't merge this; otherwise #3640 would have been merged already. There's nothing much we can do besides waiting 😅

[lpil]

Please open or participate in an issue before implementing any changes. It is unlikely that any unplanned work will be accepted as the odds of it having the intended design is very low and it's not fun to have your work rejected after you spent the time on it. Thank you