Existence of token should not be an indicator of Drive client availability

Under normal circumstances, when a user starts to use Nuxeo Drive, they

• install the Drive Client
• create a Nuxeo Drive Token
• Open with Nuxeo Drive icon is available for use.

A client discovered that if a user removes the Drive client, the UI can still prompt them to Open with Nuxeo Drive. Also, if a user starts to use Nuxeo Drive on one workstation, and then logs into Nuxeo from another workstation, the token will be available for use and the UI can prompt the user to Open with Nuxeo Drive (while the Drive client is not available on the workstation)

Client asks that these two use cases be covered:
1.when user configured Nuxeo drive in one Mac machine already ,later when user trying use Open with Nuxeo drive from other new Mac machine(Which does not have Nuxeo drive)
2.When user uninstall the Nuxeo drive in existing Mac machine, later when user trying use Open with Nuxeo drive from same machine