Display an image credit with the lead image

Content Items affected:

* Case Study
* Fatality Notice
* News Articles
* Speech
* Take Part
* World Location News Article

At the moment only the Content Publisher app supports image credits, so they will only be
displayed on news articles for the time being.

app/views/content_items/case_study.html.erb

@@ -23,6 +23,7 @@
       <%= render 'components/figure',
           src: @content_item.image["url"],
           alt: @content_item.image["alt_text"],
+          credit: @content_item.image["credit"],
           caption: @content_item.image["caption"] if @content_item.image %>
 
       <%= render 'govuk_publishing_components/components/govspeak',

app/views/content_items/fatality_notice.html.erb

@@ -25,6 +25,7 @@
       <%= render 'components/figure',
           src: @content_item.image["url"],
           alt: @content_item.image["alt_text"],
+          credit: @content_item.image["credit"],
           caption: @content_item.image["caption"] if @content_item.image %>
       <%= render 'govuk_publishing_components/components/govspeak',
           content: @content_item.body.html_safe,

app/views/content_items/news_article.html.erb

@@ -24,6 +24,7 @@
       <%= render 'components/figure',
           src: @content_item.image["url"],
           alt: @content_item.image["alt_text"],
+          credit: @content_item.image["credit"],
           caption: @content_item.image["caption"] if @content_item.image %>
       <%= render 'govuk_publishing_components/components/govspeak',
           content: @content_item.body.html_safe,

app/views/content_items/speech.html.erb

@@ -27,6 +27,7 @@
       <%= render 'components/figure',
           src: @content_item.image["url"],
           alt: @content_item.image["alt_text"],
+          credit: @content_item.image["credit"],
           caption: @content_item.image["caption"] if @content_item.image %>
 
       <%= render 'govuk_publishing_components/components/govspeak',

app/views/content_items/take_part.html.erb

@@ -18,6 +18,7 @@
     <%= render 'components/figure',
         src: @content_item.image["url"],
         alt: @content_item.image["alt_text"],
+        credit: @content_item.image["credit"],
         caption: @content_item.image["caption"] if @content_item.image %>
 
     <%= render 'govuk_publishing_components/components/govspeak',

app/views/content_items/world_location_news_article.html.erb

@@ -24,6 +24,7 @@
       <%= render 'components/figure',
           src: @content_item.image["url"],
           alt: @content_item.image["alt_text"],
+          credit: @content_item.image["credit"],
           caption: @content_item.image["caption"] if @content_item.image %>
 
       <%= render 'govuk_publishing_components/components/govspeak',