treewide: HTML Cleanup

* HTML Cleanup: Meta tags.
* Converted charset to shorthand.
* Removed meta tags with `Content-Script-Type` attribute. (Invalid in HTML5 spec.)

* HTML Cleanup: CSS tags.
* Removed `type` attribute with CSS files from link tags. (HTML5 spec recommends omitting it.)
* Removed `type` attribute from style tags. (Deprecated in HTML5 spec.)
https://html.spec.whatwg.org/#attr-link-type
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/style

* HTML Cleanup: Convert from XHTML to HTML5
* Removed XML declaration.
* Removed XML namespace.
* Changed doctype to HTML5.

* HTML Cleanup: CDATA tags.
* CDATA sections should not be used within HTML they are considered as comments and not displayed.
https://developer.mozilla.org/en-US/docs/Web/API/CDATASection

* HTML Cleanup: Script tags.
* Removed `language` attribute from script tags. (No longer valid in HTML5)
* Removed `type` attribute with JavaScript MIME type from script tags. (HTML5 spec recommends omitting it.)
https://html.spec.whatwg.org/multipage/scripting.html#attr-script-type
https://mimesniff.spec.whatwg.org/#javascript-mime-type

Signed-off-by: Mustafa Can Elmacı <mustafacan@elmaci.net>

applications/luci-app-commands/ucode/template/commands.ut

@@ -28,7 +28,7 @@
 	` });
 -%}
 
-<script type="text/javascript">//<![CDATA[
+<script>
 	function command_run(ev, id)
 	{
 		var field = document.getElementById(id);
@@ -113,7 +113,7 @@
 		ev.preventDefault();
 	}
 
-//]]></script>
+</script>
 
 {%
 	const commands = [];