Check Refresh token expiration on the client

[hasan7n]

Some users are experiencing an "Unknown or Invalid refresh token" error. This may be caused when a user leaves the MedPerf client for a month, since the refresh token lifetime is 1 month, and the error above could happen when the refresh token is expired.

For a better user experience, the MedPerf client should keep track of the refresh token lifetime and instruct the user to login again if the existing refresh token has expired.

One TODO before this: check whether the 1 month lifetime is relative to the last login timestamp, or relative to the last refresh request. (Since we use Refresh token rotation). It's not clear from the Auth0 docs, so we may test this manually with small lifetimes using the development tenant.