Use distribution/reference for parsing OCI references

[rdimitrov]

Motivation and Context

The following PR addresses the feedback from #634 around:

• Use a proper library - https://github.com/distribution/reference, instead of the implementing the OCI parsing ourselves (note: left the tests so we can ensure we are not breaking any existing behavior)
• Updating one of the error messages to now assume MCPB.

How Has This Been Tested?

Breaking Changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context