Internet midi respects start and end times (#43021)

* Play Internet Sound respects start time
For example, adding &t=400 to youtube links.
Doesn't try to parse the start time, youtube-dl does that for us already. Will probably work on most sites not just youtube.

* [Play Internet Sound] now supports end time too

Switched event handler for start to loadeddata from canplay

loadeddata fires when the first frame is available
this is quicker and more consistent than canplay, which tries
to predict at least a few moments of playability being
available before it fires

* [Internet Sound] music_extra_data now starts null

code/modules/admin/verbs/playsound.dm

@@ -67,7 +67,7 @@
 	if(istext(web_sound_input))
 		var/web_sound_url = ""
 		var/stop_web_sounds = FALSE
-		var/pitch
+		var/list/music_extra_data = list()
 		if(length(web_sound_input))
 
 			web_sound_input = trim(web_sound_input)
@@ -95,6 +95,8 @@
 					var/webpage_url = title
 					if (data["webpage_url"])
 						webpage_url = "<a href=\"[data["webpage_url"]]\">[title]</a>"
+					music_extra_data["start"] = data["start_time"]
+					music_extra_data["end"] = data["end_time"]
 
 					var/res = alert(usr, "Show the title of and link to this song to the players?\n[title]",, "No", "Yes", "Cancel")
 					switch(res)
@@ -126,7 +128,7 @@
 				var/client/C = M.client
 				if((C.prefs.toggles & SOUND_MIDI) && C.chatOutput && !C.chatOutput.broken && C.chatOutput.loaded)
 					if(!stop_web_sounds)
-						C.chatOutput.sendMusic(web_sound_url, pitch)
+						C.chatOutput.sendMusic(web_sound_url, music_extra_data)
 					else
 						C.chatOutput.stopMusic()