XWIKI-13528: Add support for replacing the default WYSIWYG editor

* Add an option to reset the default WYSIWYG editor
* Add translation keys for GWT editor's name and description

xwiki-platform-core/xwiki-platform-administration/xwiki-platform-administration-ui/src/main/resources/XWiki/AdminEditingSheet.xml

@@ -83,6 +83,9 @@
     <input type="hidden" name="objectPolicy" value="updateOrCreate" />
     <input type="hidden" name="${editorBindingClassName}_${objectNumber}_dataType" value="$dataTypeValue" />
     <select id="$fieldName" name="$fieldName">
+      ## This option is needed in order to allow the user to reset the default editor and inherit the configuration from
+      ## the parent configuration source.
+      <option value="">---</option>
       #foreach ($editor in $editors)
         #set ($editorDescriptor = $editor.descriptor)
         <option value="$escapetool.xml($editorDescriptor.id)" #if ($editorDescriptor.id == $defaultEditor)

xwiki-platform-core/xwiki-platform-wysiwyg/xwiki-platform-wysiwyg-server/src/main/resources/ApplicationResources.properties

+# ---------------------------------------------------------------------------
+# See the NOTICE file distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation; either version 2.1 of
+# the License, or (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this software; if not, write to the Free
+# Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+# 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+# ---------------------------------------------------------------------------
+
+edit.defaultEditor.org.xwiki.rendering.block.XDOM.Wysiwyg=Default WYSIWYG Editor
+edit.editor.xdomWysiwygGwt.name=GWT
+edit.editor.xdomWysiwygGwt.description=Rich text editor based on Google Web Toolkit
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