Rename `data-ve-target-container` attribute to `data-mw-ve-target-container`

Updates the data attribute for placing VE on the pages.

Bug: T310197
Change-Id: I081d5e23a15902e1429e68ac4ae191e498e6aba6

includes/templates/skin.mustache

@@ -65,9 +65,8 @@
 		{{>ArticleToolbar}}
 	{{/is-title-above-tabs}}
 
-	{{>ContentSubheader}}
-
-	<div id="bodyContent" class="vector-body">
+	<div id="bodyContent" class="vector-body" {{#is-title-above-tabs}} data-mw-ve-target-container {{/is-title-above-tabs}}>
+		{{>ContentSubheader}}
 		<div id="contentSub"{{{html-user-language-attributes}}}>{{{html-subtitle}}}</div>
 		<div id="contentSub2">{{{html-undelete-link}}}</div>
 		{{{html-user-message}}}