Stop managing example's lock file

[Yang-33]

This change updates our strategy for the examples.

1. We will stop managing lock files in the examples. The main reason is that npm audit creates too much maintenance overhead.
2. We will pin the SDK version used by the examples. Renovate will keep it up to date, so it will not become stale.

We still want to keep the ability for ourselves and contributors to use a local SDK in the examples when needed, so that workflow will remain supported.

This should make maintenance significantly easier, and user can copy example to his or her repository directly.