Handle special characters in error description for FIDO/FIDO2

[jumde]

Description:

Special characters in error descriptions for FIDO/FIDO2 result in javascript exceptions.

Steps to Reproduce

1. Navigate to demo.yubico.com/u2f
2. Insert the security key and wait for the timeout interval

Actual result:
After timeout JS exception occurs

Expected result:
Should land on the result page with the correct error

Reproduces how often: [Easily reproduced, Intermittent Issue]
Easily

[jhreis]

Should this be QA'd?

[jumde]

Added the test plan for QA

[kjozwiak]

@jumde I don't think this is working as expected. Whenever I let the Use the security key modal timeout after ~20s, I'm not seeing any errors being displayed nor am I being routed to a results page that displays an error. The modal basically disappears and the page keeps displaying Insert and tap your Yubikey with the animated spinner. Example:

[LaurenWags]

Verified passed with iPad 5th Gen using 1.11.1 (19.08.12.19)

• Verified STR from description
  

Verification PASSED on iPhone 6s+ iOS 12.4 using 1.11.1 (19.08.13.17)

• ensured that once the timeout occurs on both the Register & Authenticate modals under demo.yubico.com/u2f, an error message is correctly displayed and the page finishes loading.