Add a message alert for expired token

[gtllien]

Usecase: User is having issues using VSCode plugin not syncing instances; tried deleting folder and reinitializing the project but same issue

The issue resolved when advised to renew its api/dev token.

Expected behaviour: Add an error message/alert when the api/dev token is already expired so the user will know why the instance is not syncing, and will be able to resolve by renewing its token

[allenpigar]

Added expired token alert when making file changes in the instance.