## Context
Resolves FE-2794
Just addressing some friction points i ran into when setting up MFA for
my account under account preferences
## Changes involved
- Hitting enter at each step of setting up MFA will submit and proceed
(Previously didn't, had to click buttons)
- When logging in with MFA, automatically submit after entering 6 digits
- Refactored to use react hook form for `AddNewFactorModal` in
`FirstStep` and `SecondStep` + simplified the logic a little
2bcab95dc6