Truncate long object representations in to_repr

[liblaf]

Type of changes

• Bug fix
• New feature
• Documentation / docstrings
• Tests
• Other

Checklist

• I've run the latest black with default args on new code.
• I've updated CHANGELOG.md and CONTRIBUTORS.md where appropriate.
• I've added tests for new code.
• I accept that @willmcgugan may be pedantic in the code review.

Description

Hi Rich maintainers,

First off, thank you for creating and maintaining rich – it's an incredibly useful library that I use frequently!

This PR addresses the issue of very long object representations in tracebacks, especially when show_locals=True is enabled. Objects like large NumPy arrays, PyTorch tensors, or JAX arrays can produce extremely verbose repr() outputs, making tracebacks difficult to read and navigate.

Currently, to_repr truncates strings and bytes if they exceed max_string. This change extends similar truncation logic to the generic repr(obj) output. If max_string is set and the repr() of an object exceeds this length, it will be truncated with an ellipsis (...).

This is a partial solution that helps improve readability for general objects whose repr() is too long. It doesn't allow for type-specific custom representations, which has been discussed in issues like #3393 and PR #3394. I believe allowing external registration of __rich_repr__ or similar custom display functions would be a more comprehensive solution, as mentioned in discussion #1258. See discussion #3774.

However, I hope this small change can provide an immediate improvement for users dealing with overly long representations in tracebacks.

Thank you for your consideration and for all your work on Rich!

[willmcgugan]

Not keen on using max_string for things other than repr. Suggest max_repr.

Additionally, these two lines don't belong within the Exception block, since we aren't expecting this code to throw exceptions.