Run task to completion in `wasmtime run --invoke 'foo()'`

[dicej]

Currently, wasmtime run's invoke_component function uses Func::call_async to invoke the function. However, that will only run the guest task until it produces a result, then print that result and exit. Ideally, it would use Func::call_concurrent instead, which returns a TaskExit which can be used to await the completion of the task, allowing any post-return operations to finish.

[vados-cosmonic]

Hey just to check, this was resolved by #12185, right?

[alexcrichton]

That handled executing the wasi:cli/run function, but this is the follow-up for --invoke which manually selects a function and invokes it. Effectively this needs to use call_concurrent and then use the second TaskExit return value