Fix the "your account has an issue" error when resetting with a trivial password

[alexwlchan]

Steps to reproduce:

1. Click "forgot password" on the sign-in screen
2. When you get the reset password email and open the form, enter the password Aaaaaaa0
3. Click "reset password"

You get an error:

There is an issue with this library account. To resolve this, please contact Library Enquiries ([email protected])

This should tell you to use a more complex password instead.

[alexwlchan]

Happy to work on this together with somebody.

[jamieparkinson]

Follows on from wellcomecollection/wellcomecollection.org#7816; password triviality is determined by Sierra as per https://documentation.iii.com/sierrahelp/Default.htm#sgwpac/sgwpac_using_pins.html