remove unused showConfirmationDialog appview

Everything is linked to window.confirmationDialog()

js/background.js

@@ -987,16 +987,6 @@
       }
     });
 
-    Whisper.events.on('showConfirmationDialog', options => {
-      if (
-        appView &&
-        appView.inboxView &&
-        appView.inboxView.conversation_stack
-      ) {
-        appView.inboxView.conversation_stack.showConfirmationDialog(options);
-      }
-    });
-
     Whisper.events.on('showNicknameDialog', options => {
       if (appView) {
         appView.showNicknameDialog(options);

js/views/conversation_view.js

@@ -936,27 +936,6 @@
       }
     },
 
-    destroyMessages() {
-      const message = this.model.isPublic()
-        ? i18n('deletePublicConversationConfirmation')
-        : i18n('deleteConversationConfirmation');
-
-      Whisper.events.trigger('showConfirmationDialog', {
-        message,
-        onOk: async () => {
-          try {
-            await this.model.destroyMessages();
-            this.unload('delete messages');
-          } catch (error) {
-            window.log.error(
-              'destroyMessages: Failed to successfully delete conversation',
-              error && error.stack ? error.stack : error
-            );
-          }
-        },
-      });
-    },
-
     showSendConfirmationDialog(e, contacts) {
       let message;
       const isUnverified = this.model.isUnverified();

js/views/inbox_view.js

@@ -30,23 +30,6 @@
         $el.remove();
       }
     },
-    showConfirmationDialog({
-      title,
-      message,
-      messageSub,
-      onOk,
-      onCancel,
-      hideCancel,
-    }) {
-      window.confirmationDialog({
-        title,
-        message,
-        resolve: onOk,
-        reject: onCancel,
-        hideCancel,
-        messageSub,
-      });
-    },
     setupSessionConversation() {
       // Here we set up a full redux store with initial state for our Conversation Root