Added Identity operator

[Swopper050]

Closes #48

[Copilot]

Pull Request Overview

This pull request adds the new Identity operator to support ONNX identity functionality and includes corresponding tests. Key changes include:

• Adding the Identity operator implementation (ops/identity/identity.go) and its versioning file (ops/identity/versions.go).
• Updating the operator map in opset.go to include the Identity operator.
• Adding unit tests for the Identity operator in ops/identity/identity_test.go and updating test lists in ops_test.go.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
opset.go	Added import and map entry for the Identity operator.
ops_test.go	Updated test lists to include Identity operator tests and an ignored "test_identity_opt".
ops/identity/versions.go	Created versioning for the Identity operator.
ops/identity/identity_test.go	Added tests validating the behavior and inputs of the Identity operator.
ops/identity/identity.go	Implemented the Identity operator functionality.

Comments suppressed due to low confidence (1)

ops_test.go:85

• [nitpick] Consider clarifying the comment for 'test_identity_opt' to provide explicit context or a reference to a bug report if this test is intentionally ignored due to a known issue.

"test_identity_opt", // Bug in test? Can't read in input tensor.