added see al org's page and menu item, made fields configurable for actor

src/Plugin/Menu/SeeAllOrganisationsMenuLink.php

@@ -0,0 +1,9 @@
+<?php
+namespace Drupal\opencase\Plugin\Menu;
+
+use Drupal\Core\Menu\MenuLinkDefault;
+
+/**
+ * Represents a menu link for seeing all organisations of various types.
+ */
+class SeeAllOrganisationsMenuLink extends MenuLinkDefault {}