when plugin is installed outside of a Dotscience install, show link to Dotscience

[lukemarsden]

Users can install dotscience jupyterlab-plugin in any Jupyter instance (outside of Dotscience) but it won't work.

In that case (if API calls to the agent are failing), show a message in the plugin stating:

In order to use the Dotscience Jupyter plugin, run Jupyter within Dotscience.
<a href="https://dotscience.com">Try it free</a>

Also disable fullstory tracking in this case.

We need to disable this tracking in the dotscience-aws case as well.