fix: conv_general differences between gpu, cpu

[aturker1]

Proposed changes

Fixes inconsistencies in conv_general results between GPU and CPU implementations by properly handling asymmetric padding in the CPU backend. Implements separate padding_lo and padding_hi parameters throughout the convolution code. Addresses issue #2038.

Checklist

Put an x in the boxes that apply.

• [x] I have read the CONTRIBUTING document
• [x] I have run pre-commit run --all-files to format my code / installed pre-commit prior to committing changes
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] I have updated the necessary documentation (if needed)

[awni]

@aturker1 the tests are failing on this PR. Are you planning to come back to it?

[aturker1]

@awn Ah yes, I am going to fix it thid weekend.

[awni]

Would you mind adding a test for this which exposed the issue in the first place?