R1:e91bc26da685

Don't rate limit users clicking "Wait Patiently" at an MFA gate even if they typed some text earlier

Summary:
Depends on D20017. Ref T13222. Currently, if you:

- type some text at a TOTP gate;
- wait ~60 seconds for the challenge to expire;
- submit the form into a "Wait patiently" message; and
- mash that wait button over and over again very patiently

...you still rack up rate limiting points, because the hidden text from your original request is preserved and triggers the "is the user…