sdk: introduce proto-oxford feature flag

Context

add proto oxford to feature flag to the sdk. Only the feature I need to use is added, I have not checked what others "proto-alpha" feature should be replaced to proto-oxford.

Next MR that uses that feature flag: !12904 (merged)

Manually testing the MR

try to compile the sdk or a kernel using the proto-oxford feature flag.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR