Implement "send_link" macro (#6767)

When to_chat gets converted to a proc, then the construct of to_chat(some, link(url)) will no longer work. Or will produce odd results.

As a result, the send_link macro is now created. Replaced existent instances of the previous construct and added a simple grep check for this as well. It won't catch all, probably, but it'll catch the most common instances.

code/modules/mob/abstract/new_player/poll.dm

@@ -46,7 +46,7 @@
 			link = select_query.item[1]
 
 		if(link && link != "")
-			to_chat(usr, link(link))
+			send_link(usr, link)
 		else
 			log_debug("Polling: [usr.ckey] tried to open poll [pollid] with a invalid link: [link]")