`dynamic_add_media` freezes mapblock loading until it's done

[Zughy]

Luanti version

5.15.1

Operating system and version

Pop!_OS 22.04 LTS

CPU model

No response

GPU model

No response

Active renderer

No response

Summary

Mapblocks stop loading when dynamic_add_media is called, until the media file has finished loading. Not sure if it's intended behaviour, however if I load some BGM and teleport someone at the same time I guess it's not the best feeling

Steps to reproduce

1. Create a test_media folder in the world folder you want to test this snippet
2. Put a large my_large_track.ogg sound (~10MB) in such folder
3. code

core.register_on_joinplayer(function(player)
	local p_name = player:get_player_name()
	core.after(3, function()
		core.chat_send_player(p_name, "Loading")
		core.dynamic_add_media({filepath = core.get_worldpath() .. "/test_media/my_large_track.ogg", to_player = p_name, client_cache = false}, function(name) core.chat_send_all("Loaded") end)
	end)
end)

[sfan5]

Media transfer and block data use the same network protocol channel, so either will block the other.
This is unavoidable right now. #10699 would have fixed this, but this is also something we should look at improving when we replace the protocol implementation.