Extract webvieweditor to share between compose page and signature editor (#578)

* initial work for webview editor control

* moved more stuff to editor itself

* revert packages.props indention changes

* move alignment logic

* Migrate signature editor to new control

* move background to editor control

* Some polishing

* Fixed the corner glitch issue with dark theme.

---------

Co-authored-by: Burak Kaan Köse <bkaankose@outlook.com>

Wino.Mail/JS/editor.js

@@ -115,7 +115,7 @@ function SetDarkEditor() {
 
 function toggleToolbar(enable) {
     const toolbar = document.querySelector('.jodit-toolbar__box');
-    if (enable == 'true') {
+    if (enable) {
         toolbar.style.display = 'flex';
     }
     else {