Remove the hidden <dialog> About template from cool.html.m4.

The About dialog is now fully created and filled in JavaScript using:
- createAboutDialogContent() to build the structure
- window.app.serverInfo to provide version and server details
- populateAboutDialog() to insert all content and branding

- This removes the need for duplicated HTML in the template file and makes
  the dialog easier to maintain.

- A minimal empty <div id=\"about-dialog\" tabIndex=\"0\"></div> is kept in the
  HTML to preserve Notebookbar About tab detection

Signed-off-by: Banobe Pascal <[email protected]>
Change-Id: Id0bea4b6892b62fe4a9396c8d941f79ee5e39b97

Author: banobepascal

browser/html/cool.html.m4

@@ -213,37 +213,7 @@ m4_ifelse(MOBILEAPP,[true],
     </div>
 
     <!-- Remove if you don't want the About dialog -->
-    <dialog>
-      <div id="about-dialog" tabIndex="0">
-        <div id="about-dialog-header">
-          <fig id="integrator-logo"></fig>
-          <h1 id="product-name">Collabora Online</h1>
-        </div>
-        <hr/>
-        <div id="about-dialog-container">
-          <div id="about-dialog-logos">
-            <fig id="product-logo"></fig>
-            <fig id="lokit-logo"></fig>
-          </div>
-          <div id="about-dialog-info-container">
-            <div id="about-dialog-info">
-              <div id="coolwsd-version-label"></div>
-              <div class="about-dialog-info-div"><div id="coolwsd-version" dir="ltr"></div></div>
-              <div class="spacer"></div>
-              <div id="lokit-version-label"></div>
-              <div class="about-dialog-info-div"><div id="lokit-version" dir="ltr"></div></div>
-              m4_ifelse(MOBILEAPP,[],[<div id="served-by"><span id="served-by-label"></span>&nbsp;<span id="os-info"></span>&nbsp;<wbr><span id="coolwsd-id"></span></div>],[<p></p>])
-              <div id="slow-proxy"></div>
-              m4_ifelse(DEBUG,[true],[<div id="js-dialog">JSDialogs: <a href="#">View widgets</a></div>])
-              <div id="routeToken"></div>
-              <div id="timeZone"></div>
-              m4_ifelse(MOBILEAPP,[],[<div id="wopi-host-id">%WOPI_HOST_ID%</div>],[<p></p>])
-              <p class="about-dialog-info-div"><span dir="ltr">Copyright © _YEAR_, VENDOR.</span></p>
-            </div>
-          </div>
-        </div>
-      </div>
-    </dialog>
+    <div id="about-dialog" tabIndex="0"></div>
 
 m4_ifelse(MOBILEAPP, [true],
      [