Add replace_html to tgwindows (for real this time) (#67137)

adds the ability to realtime inject HTML into TGWindow instances, just as you can create TGWindow instances with inline_html at initialization.

Co-authored-by: Aleksej Komarov <stylemistake@gmail.com>

code/modules/tgui/tgui_window.dm

@@ -311,6 +311,18 @@
 			: "[id].browser:update")
 	message_queue = null
 
+/**
+ * public
+ *
+ * Replaces the inline HTML content.
+ *
+ * required inline_html string HTML to inject
+ */
+/datum/tgui_window/proc/replace_html(inline_html = "")
+	client << output(url_encode(inline_html), is_browser \
+		? "[id]:replaceHtml" \
+		: "[id].browser:replaceHtml")
+
 /**
  * private
  *