core: new my_view_mode_raw_text_content field

This field is intended to display not authored by the user, typically machine generated, technical text.
The text is displayed with a monospace font and spellchecker is disabled.

product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_core/Base_viewFieldLibrary.xml

@@ -158,6 +158,7 @@
                         <string>my_view_mode_reference_as_name</string>
                         <string>my_gadget_field</string>
                         <string>my_iframe_gadget_field</string>
+                        <string>my_view_mode_raw_text_content</string>
                       </list>
                     </value>
                 </item>