Patch/authentication exception

What I did

• Changed 'Token not found' to throw a standard \Exception rather than a DF_REST_Exception, as "Token Not Found" is not a message that should make its way out to the user.

Implications

Laravel-side API calls that strike this circumstance now get a 500 response with {message: "Server Error"}.

Setup

None

How to test

• Code review.
• Test with Art Money projects; create the situation by e.g. a code change to force this to happen.
• Confirm that the response to the Laravel-side call no longer uses the format for error messages intended for the user, i.e.

{
  result: "error"
  errors: ["Token Not Found"]
}