* Factor out a common TestHtmlParser
Looks like I'm doing this in a few different places.
* Improve OIDC login test
Complete the OIDC login flow, rather than giving up halfway through.
* Ensure that OIDC login works with multiple OIDC providers
* Fix bugs in handling clientRedirectUrl
- don't drop duplicate query-params, or params with no value
- allow utf-8 in query-params
The final part (for now) of my work to implement a username picker in synapse itself. The idea is that we allow
`UsernameMappingProvider`s to return `localpart=None`, in which case, rather than redirecting the browser
back to the client, we redirect to a username-picker resource, which allows the user to enter a username.
We *then* complete the SSO flow (including doing the client permission checks).
The static resources for the username picker itself (in
https://github.com/matrix-org/synapse/tree/rav/username_picker/synapse/res/username_picker)
are essentially lifted wholesale from
https://github.com/matrix-org/matrix-synapse-saml-mozilla/tree/master/matrix_synapse_saml_mozilla/res.
As the comment says, we might want to think about making them customisable, but that can be a follow-up.
Fixes#8876.
This PR adds a confirmation step to resetting your user password between clicking the link in your email and your password actually being reset.
This is to better align our password reset flow with the industry standard of requiring a confirmation from the user after email validation.