Create a name fix pass to ensure unique names for all values and nodes

[Copilot]

This PR implements a NameFixPass in src/onnx_ir/passes/common/naming.py to ensure that all values and nodes in an ONNX IR model have unique names according to the specified policy:

1. Graph inputs and outputs have precedence - Their names are preserved when possible, and only renamed if duplicates exist
2. Scoped unique names: Names in subgraphs are unique within their naming scopes and their parent scopes.
3. Subgraph inputs/outputs are processed
4. Support custom naming generators with generate_node_name and generate_value_name params.

I create the enter_graph and exit_graph callbacks on the RecursiveIterator to allow users to handle getting into and out of graph scopes.

[justinchuby]

You should maintain a ir.Value to assigned name dictionary to ensure that a value is only assigned a name once. Alternatively maintain a set of seen values.

[codecov]

Codecov Report

❌ Patch coverage is 87.02290% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.40%. Comparing base (4a775d0) to head (8f213bf).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/onnx_ir/passes/common/naming.py	88.79%	6 Missing and 7 partials ⚠️
src/onnx_ir/traversal.py	71.42%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #124      +/-   ##
==========================================
+ Coverage   76.03%   76.40%   +0.36%     
==========================================
  Files          39       40       +1     
  Lines        4586     4717     +131     
  Branches      899      929      +30     
==========================================
+ Hits         3487     3604     +117     
- Misses        818      827       +9     
- Partials      281      286       +5     

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[Copilot]

You should maintain a ir.Value to assigned name dictionary to ensure that a value is only assigned a name once. Alternatively maintain a set of seen values.

I've updated the implementation to use a dict[ir.Value, str] mapping instead of a set to track processed values. This ensures each value is assigned a name exactly once and makes the intent clearer. The dictionary explicitly maps each ir.Value to its final assigned name. Commit: b979a3d

[github-advanced-security]

lintrunner found more than 20 potential problems in the proposed changes. Check the Files changed tab for more details.