ns for fx: improve error messages for graph matching (#61359)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61359
Makes the error messages when graph matching easier to read
for users.
Test Plan:
```
// inspect the exceptions in the following two tests and verify
// that they are easier to read than before
python test/test_quantization.py TestFXGraphMatcher.test_matching_failure_node_count
python test/test_quantization.py TestFXGraphMatcher.test_matching_failure_node_type
```
Imported from OSS
Reviewed By: hx89
Differential Revision: D29600353
fbshipit-source-id: ec6640fe6cab7b62a697e4ee385be182f2918fd4
