LUT-31028 : add preview in modify blog

Author: Jeremy Deloche

src/java/fr/paris/lutece/plugins/blog/resources/blog_messages.properties

@@ -192,6 +192,7 @@ modify_blog.labelToolbarLabel=Post management toolbar
 modify_blog.labelUpdate=Update
 modify_blog.labelSave=Save
 modify_blog.returnToActualVersion=Return to the current version
+modify_blog.labelPreview=Preview
 
 history_blog.pageTitle=History
 history_blog.title=History of this post

src/java/fr/paris/lutece/plugins/blog/resources/blog_messages_fr.properties

@@ -185,6 +185,7 @@ modify_blog.labelToolbarLabel=Boutons de gestion du billet
 modify_blog.labelUpdate=Actualiser
 modify_blog.labelSave=Enregistrer
 modify_blog.returnToActualVersion=Revenir \u00e0 la version actuelle
+modify_blog.labelPreview=Pr\u00e9evisualiser
 
 history_blog.pageTitle=Historique du billet
 history_blog.title=Liste des modification du billet

webapp/WEB-INF/templates/admin/plugins/blog/modify_blog.html

@@ -20,6 +20,7 @@
         <#if actual_blog_version?? >
           <@aButton class='btn-notif me-1' color='danger' href='jsp/admin/plugins/blog/ManageBlogs.jsp?view=modifyBlog&id=${blog.id}&blog_version=${actual_blog_version}' title='#i18n{blog.modify_blog.returnToActualVersion}' hideTitle=['xs','sm', 'md'] buttonIcon='history' size='' />
         </#if>
+        <@aButton class='me-1' href='jsp/admin/plugins/blog/ManageBlogs.jsp?view=previewBlog&id=${blog.id}&blog_version=${blog.version}' title='#i18n{blog.modify_blog.labelPreview}' hideTitle=['all']  color='default' size='' buttonIcon='eye' />
         <@offcanvas id='blog-properties' title='#i18n{blog.modify_blog.labelProperties}' btnTitle='#i18n{blog.modify_blog.labelProperties}' position='end' btnIcon='cog me-2'>
           <@box class='mt-3'>
             <@boxHeader title='#i18n{blog.modify_blog.TagsTitle}'>