1842 add expiration date/time to user account

[roslynwythe]

Fixes #1842

What changes did you make?

• at the server, add new property expiration to the user object
• at the client, check for expiration in TdmAuthProvider. If the expiration time has passed, the user account object is set to null, in state, UserContext and local Storage
• updated various components to prevent them from accessing properties of the account object after it has been set to null.

Why did you make the changes (we will use this info to test)?

• Since the expiration time was not checked periodically, the website did not respond promptly when an account expired, and so the user was permitted to initiate actions (such as editing the FAQ) that could not be completed.
• The solution in this PR involves only the client and so it is not able to detect situations where the user is logged out from a separate browser tab. A more complete solution would have the client poll the server for user account status or would have the server initiate communication with the client upon change to user account status.

Screenshots of Proposed Changes Of The Website (if any, please do not screen shot code changes)

There were no visual changes to the website

[entrotech]

I'm just going to approve without extensive testing. Not sure why all the optional chaining operations weren't required before. Maybe other logic prevented that code from executing if the user wasn't logged in. There might have been edge cases where it would have caused a problem.

[entrotech]

Found a bug in this PR that caused the Admin Notes and Date Admin Modified columns to be hidden (though the column headings were still shown.