add optional support for tokio-console

This turned out to be quite hairy, mostly because we need to apply the
config's log level filter to the actual logs (stdout and, optionally
sentry), but do not want to filter out the tokio tracing events needed by
the console_subscriber. I hit several edge cases in tracing getting
this to work, and we now depend on a git version of tracing with a
backported patch :(

src/service/admin/debug/debug_commands.rs

@@ -331,7 +331,7 @@ pub(crate) async fn change_log_level(
 		match services()
 			.globals
 			.tracing_reload_handle
-			.modify(|filter| *filter = old_filter_layer)
+			.reload(&old_filter_layer)
 		{
 			Ok(()) => {
 				return Ok(RoomMessageEventContent::text_plain(format!(
@@ -360,7 +360,7 @@ pub(crate) async fn change_log_level(
 		match services()
 			.globals
 			.tracing_reload_handle
-			.modify(|filter| *filter = new_filter_layer)
+			.reload(&new_filter_layer)
 		{
 			Ok(()) => {
 				return Ok(RoomMessageEventContent::text_plain("Successfully changed log level"));