code deprecation after #4697 reaches production

[GitHK]

After PR #4697 is released in production the following legacy compatibility changes can be made.

SharedStore legacy format updates

Inside services/dynamic-sidecar/tests/unit/test_models_shared_store.py remove following block:

    # remove properties which have been added but did not exit
    # when the legacy format was created
    # NOTE this was already parsed so this check is a regression
    # to check compatibility with very old formats
    parsed_legacy_format.pop("original_to_container_names")

Inside services/dynamic-sidecar/tests/mocks/legacy_shared_store.json extend the legacy json with "original_to_container_names": {}