Support for async node functions (#8830)

* Support for async execution functions

This commit adds support for node execution functions defined as async. When
a node's execution function is defined as async, we can continue
executing other nodes while it is processing.

Standard uses of `await` should "just work", but people will still have
to be careful if they spawn actual threads. Because torch doesn't really
have async/await versions of functions, this won't particularly help
with most locally-executing nodes, but it does work for e.g. web
requests to other machines.

In addition to the execute function, the `VALIDATE_INPUTS` and
`check_lazy_status` functions can also be defined as async, though we'll
only resolve one node at a time right now for those.

* Add the execution model tests to CI

* Add a missing file

It looks like this got caught by .gitignore? There's probably a better
place to put it, but I'm not sure what that is.

* Add the websocket library for automated tests

* Add additional tests for async error cases

Also fixes one bug that was found when an async function throws an error
after being scheduled on a task.

* Add a feature flags message to reduce bandwidth

We now only send 1 preview message of the latest type the client can
support.

We'll add a console warning when the client fails to send a feature
flags message at some point in the future.

* Add async tests to CI

* Don't actually add new tests in this PR

Will do it in a separate PR

* Resolve unit test in GPU-less runner

* Just remove the tests that GHA can't handle

* Change line endings to UNIX-style

* Avoid loading model_management.py so early

Because model_management.py has a top-level `logging.info`, we have to
be careful not to import that file before we call `setup_logging`. If we
do, we end up having the default logging handler registered in addition
to our custom one.

comfy/utils.py

@@ -998,11 +998,12 @@ def set_progress_bar_global_hook(function):
     PROGRESS_BAR_HOOK = function
 
 class ProgressBar:
-    def __init__(self, total):
+    def __init__(self, total, node_id=None):
         global PROGRESS_BAR_HOOK
         self.total = total
         self.current = 0
         self.hook = PROGRESS_BAR_HOOK
+        self.node_id = node_id
 
     def update_absolute(self, value, total=None, preview=None):
         if total is not None:
@@ -1011,7 +1012,7 @@ class ProgressBar:
             value = self.total
         self.current = value
         if self.hook is not None:
-            self.hook(self.current, self.total, preview)
+            self.hook(self.current, self.total, preview, node_id=self.node_id)
 
     def update(self, value):
         self.update_absolute(self.current + value)