DEV: convert PrivateMessageMap widget to glimmer components (#25837)

* DEV: add map system test for private message map
* DEV: convert PrivateMessageMap to glimmer components

spec/system/page_objects/components/private_message_map.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+module PageObjects
+  module Components
+    class PrivateMessageMap < PageObjects::Components::Base
+      PRIVATE_MESSAGE_MAP_KLASS = ".private-message-map"
+      def is_visible?
+        has_css?(PRIVATE_MESSAGE_MAP_KLASS)
+      end
+
+      def participants_details
+        find("#{PRIVATE_MESSAGE_MAP_KLASS} .participants").all(".user")
+      end
+
+      def participants_count
+        participants_details.length
+      end
+
+      def controls
+        find("#{PRIVATE_MESSAGE_MAP_KLASS} .controls")
+      end
+
+      def toggle_edit_participants_button
+        controls.click_button(class: "add-remove-participant-btn")
+      end
+
+      def has_add_participants_button?
+        controls.has_button?(class: "add-participant-btn")
+      end
+
+      def has_no_add_participants_button?
+        controls.has_no_button?(class: "add-participant-btn")
+      end
+      def click_add_participants_button
+        controls.click_button(class: "add-participant-btn")
+      end
+
+      def click_remove_participant_button(user)
+        find_link(user.username).sibling(".remove-invited").click
+      end
+
+      def has_participant_details_for?(user)
+        find("#{PRIVATE_MESSAGE_MAP_KLASS} .participants").has_link?(
+          class: "user-link",
+          href: "/u/#{user.username}",
+        )
+      end
+
+      def has_no_participant_details_for?(user)
+        find("#{PRIVATE_MESSAGE_MAP_KLASS} .participants").has_no_link?(
+          class: "user-link",
+          href: "/u/#{user.username}",
+        )
+      end
+    end
+  end
+end