Add the current_shop and session_token to assigns making them available in live view templates.

Get options that should be passed to live_session.

This is useful for integrating with other tools that require a custom live_session, like beacon_live_admin. For example:

beacon_live_admin ShopifexWeb.LiveSession.opts(...beacon_opts) do
  ...
end

Return a map of session values to include in the liveview session. This will be merged with other session values and available in the on_mount.