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>

test/controllers/onboardings_controller_test.rb

@@ -82,7 +82,7 @@ class OnboardingsControllerTest < ActionDispatch::IntegrationTest
   test "should get goals" do
     get goals_onboarding_url
     assert_response :success
-    assert_select "h1", text: /What brings you to Sure/i
+    assert_select "h1", text: /What brings you here/i
   end
 
   test "should get trial" do