Make branding configurable (#173)

* Remove orphan function

* Add centralized branding helpers and update locales

* Remove _plus and add (proper) brand

* No longer Sure, configurable

* Consistency with compose file naming

* Missed `product_name` mapping

* Fix brand/product name in mailers

* Product name in email reset flow

* Fix i18n errors/tests

* Fix password mailer brand/product name (again)

* Missed hardcoded `Sure` in onboarding goals

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Signed-off-by: Juan José Mata <jjmata@jjmata.com>

* PR nitpick on documentation

* Missing interpolation key for invited UI

* Orphan assets

* New logos

---------

Signed-off-by: Juan José Mata <jjmata@jjmata.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

app/views/invitation_mailer/invite_email.html.erb

@@ -1,9 +1,12 @@
-<h1><%= t(".greeting") %></h1>
+<h1><%= t(".greeting", product: product_name) %></h1>
 
 <p>
-  <%= t(".body",
+  <%= t(
+    ".body",
     inviter: @invitation.inviter.display_name,
-    family: @invitation.family.name).html_safe %>
+    family: @invitation.family.name,
+    product: product_name
+  ).html_safe %>
 </p>
 
 <%= link_to t(".accept_button"), @accept_url, class: "button" %>