[shell] feat: close event on child process

[Ludea]

it could be awesome if this plugin get an event on closed child.

https://doc.rust-lang.org/std/process/struct.Child.html#method.wait

[FabianLars]

The command does emit a close event: https://v2.tauri.app/reference/javascript/shell/#example-1

Is that what you're asking for?

[Ludea]

Not at all, close event for spawned child process, not command

[Ludea]

#1947