Change full logo to use primary text color of the given theme (#10994)

* Change full logo to use primary text color of the given theme

* Fix colors of public layout header in light theme

app/views/about/show.html.haml

@@ -8,7 +8,7 @@
 .landing
   .landing__brand
     = link_to root_url, class: 'brand' do
-      = image_pack_tag 'logo_full.svg', alt: 'Mastodon'
+      = svg_logo_full
       %span.brand__tagline=t 'about.tagline'
 
   .landing__grid

app/views/layouts/application.html.haml

@@ -36,3 +36,4 @@
 
     %div{ style: 'display: none'}
       = render file: Rails.root.join('app', 'javascript', 'images', 'logo_transparent.svg')
+      = render file: Rails.root.join('app', 'javascript', 'images', 'logo_full.svg')

app/views/layouts/auth.html.haml

@@ -6,7 +6,7 @@
     .logo-container
       %h1
         = link_to root_path do
-          = image_pack_tag 'logo_full.svg', alt: 'Mastodon'
+          = svg_logo_full
 
     .form-container
       = render 'flashes'

app/views/layouts/public.html.haml

@@ -8,7 +8,7 @@
         %nav.header
           .nav-left
             = link_to root_url, class: 'brand' do
-              = image_pack_tag 'logo_full.svg', alt: 'Mastodon'
+              = svg_logo_full
 
             = link_to t('directories.directory'), explore_path, class: 'nav-link optional' if Setting.profile_directory
             = link_to t('about.about_this'), about_more_path, class: 'nav-link optional'