Move signalling utils to protocol so that both server and Go SDK can use

[boks1971]

it.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 51d7cd6

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

💥 An error occurred when fetching the changed packages and changesets in this PR

Some errors occurred when validating the changesets config:
The package or glob expression "github.com/livekit/protocol" specified in the `fixed` option does not match any package in the project. You may have misspelled the package name or provided an invalid glob expression. Note that glob expressions must be defined according to https://www.npmjs.com/package/micromatch.