Plug that redirects users who must change their password.
When a user has must_change_password: true set on their record
(typically by an admin via Sigra.Account.require_password_change/2),
this plug calls the error handler with :must_change_password and halts
the connection, forcing them to the password change form.
This mirrors the Sigra.Plug.RequireSudo pattern.
Options
:error_handler- Required. Module implementingSigra.Plug.ErrorHandler.
Example
plug Sigra.Plug.RequirePasswordChange,
error_handler: MyAppWeb.AuthErrorHandler