[Xiaoyu Z (xiaoyu-work)]

Describe your changes

Exact, destination-owned copy of #2717 for independent tracking. Do not merge this draft. No commits were rewritten or implementation changes added.

• Source: preetha-intel/Olive:feature/openvino-model-package
• Destination: microsoft/Olive:feature/openvino-model-package
• Base: main
• Preserved head: 9bc198eff22a2dcd4308278f4ac236b4a65e77ac

The copied change adds an OpenVINOModelPackage pass to compile ONNX models into OpenVINO EPContext variants and assemble ONNX Runtime .ortpackage outputs with shared weights. It supports compilation and package-only modes, extends EPContextBinaryGenerator to OpenVINO, and includes documentation, an example configuration, and unit tests.

Copy verification: All four commands below passed and resolved to the preserved head:

git rev-parse --verify "refs/heads/feature/openvino-model-package"
git rev-parse --verify "refs/remotes/origin/feature/openvino-model-package"
git ls-remote --heads "https://github.com/preetha-intel/Olive.git" "refs/heads/feature/openvino-model-package"
git ls-remote --heads origin "refs/heads/feature/openvino-model-package"

Unit tests, model execution, and lintrunner -a were not run for this unchanged branch copy. The existing dirty worktree was left on main without checking out the copied branch or modifying its files.

Release note: Add OpenVINO model packaging for ONNX Runtime, including per-device compilation and assembly from precompiled EPContext models.

Checklist before requesting a review

• Add unit tests for this change.
• Make sure all tests can pass.
• Update documents if necessary.
• Lint and apply fixes to your code by running lintrunner -a
• Is this a user-facing change? If yes, give a description of this change to be included in the release notes.

(Optional) Issue link

Original PR: #2717