[Feature Request] Feature test confirming unhandled-command update behavior

Describe the solution you'd like

Every SDK needs a feature test that confirms that an update is properly processed if it is received while a task that tries to complete the workflow is processing. The test needs to make sure it receives and processes the update before complete (and no cheating like making the workflow function wait on update). This is probably something like:

@workflow.defn
class MyWorkflow:
    def __init__(self) -> None:
        self.result = "done"

    @workflow.run
    async def run(self) -> str:
        # <possibly inject some artificial task hang here on first task attempt>
        return self.result

    @workflow.update
    async def update(self) -> None:
        self.result = "done-from-update"

Then make sure an update is sent while the initial task is processed, causing unhandled command (assert this occurs if possible), and that the workflow result is "done-from-update".

A test like this hopefully helps us confirm that 1) server unhandled-command processing of updates works properly, and 2) coroutine ordering of the update coroutine will make sure it runs before workflow complete.

EDIT: Actually, unhandled command causes full replay. So we probably also need a test that operates on cache. Something like:

@workflow.defn
class MyWorkflow:
    def __init__(self) -> None:
        self.results = []

    @workflow.run
    async def run(self) -> List[str]:
        await workflow.wait_condition(lambda: self.results)
        return self.results

    @workflow.signal
    async def signal(self) -> None:
        self.result.append("got-signal")

    @workflow.update
    async def update(self) -> None:
        self.result.append("got-update")

And make sure that the signal and update are in the same task and in that order (i.e. stop the worker after first task processed before sending signal + update) and that the workflow returns with both values (i.e. signal isn't the only thing processed).

No files or existing tests are named in the issue. Start by locating the SDK feature-test suites and the workflow, update, signal, and task-processing entry points described here. Done means coverage confirms an update during completion affects the workflow result and that replay or cache handling preserves both the signal and update results.