Update markup of templates to Bootstrap 5 (#173)

* Update markup of all buttons, forms and input elements to Bootstrap 4

* Add documentByLine in the card-header. Add commentBody in the card-body

* Update CHANGES.txt

* Update @@manage-comments.pt moderation interface with Bootstrap 4

* bs5 form updates

* add bootstrap icon from resolver

* update bindings for button

* update markup for bootstrap 5

* turn configlet portlets into menu

* turn configlet portlets into menu (2)

* bootstrap b1 changes

* major version bump

Co-authored-by: Peter Holzer <peter.holzer@agitator.com>
Co-authored-by: Jens W. Klein <jk@kleinundpartner.at>
Co-authored-by: Peter Mathis <peter.mathis@kombinat.at>

plone/app/discussion/profiles/default/controlpanel.xml

@@ -11,7 +11,7 @@
         appId="plone.app.discussion"
         category="plone-general"
         condition_expr=""
-        icon_expr="string:${portal_url}/discussionitem_icon.png"
+        icon_expr="string:chat-square-dots"
         url_expr="string:${portal_url}/@@discussion-controlpanel"
         visible="True"
         i18n:attributes="title">