Easy way to link tokio JoinHandle with component to abort on unmount

[namse]

Most of time, spawned tokio task should be aborted, so we need to pass that JoinHandle or AbortHandle to ctx.

It would be better to spawn task from ctx, like ctx.task(async move { ... }); then let handle = tokio::spawn(async move {...}); ctx.abort_on_unmount(handle); because it's too long.