Rewrite MFA function

[mar235av]

The use (or not) of MFA in our Shibboleth deployment is controlled by a 450 line Javascript function with confusing logic flow. This is not even close to good coding practice, is error prone and difficult to modify when needed. On the positive side, we do have rigorous automated testing that establishes that this code works as intended, so the risk is contained.

Best practice would be to re-write this function as a Java plugin with rigorous design and logic flow with unit tests for confirmation. This is likely 1-2 weeks of work.

An alternative is to not do this work in anticipation that some other system would take over the MFA logic, allowing us to retire this function rather than re-writing it.