FEATURE: Implement 2factor login TOTP

implemented review items.

Blocking previous codes - valid 2-factor auth tokens can only be authenticated once/30 seconds.
I played with updating the “last used” any time the token was attempted but that seemed to be overkill, and frustrating as to why a token would fail.
Translatable texts.
Move second factor logic to a helper class.
Move second factor specific controller endpoints to its own controller.
Move serialization logic for 2-factor details in admin user views.
Add a login ember component for de-duplication
Fix up code formatting
Change verbiage of google authenticator

add controller tests:
second factor controller tests
change email tests
change password tests
admin login tests

add qunit tests - password reset, preferences

fix: check for 2factor on change email controller
fix: email controller - only show second factor errors on attempt
fix: check against 'true' to enable second factor.

Add modal for explaining what 2fa with links to Google Authenticator/FreeOTP

add two factor to email signin link

rate limit if second factor token present

add rate limiter test for second factor attempts

app/views/session/email_login.html.erb

@@ -3,6 +3,18 @@
     <%= @error %>
   </div>
 <%end%>
+<%if @second_factor_required%>
+  <div style="display: flex;">
+    <div style="margin: auto;">
+      <%= form_tag(method: "post") do%>
+        <h2><%=t "login.second_factor_title" %></h2>
+        <%= label_tag(:second_factor_token, t("login.second_factor_description")) %>
+        <div><%= text_field_tag(:second_factor_token) %></div>
+        <%= submit_tag(t("login.submit"), class: "btn btn-large btn-primary") %>
+      <%end%>
+    </div>
+  </div>
+<%end%>
 
 <% content_for :title do %><%=t "email_login.title" %><% end %>