ComfyAPI Core v0.0.2 (#8962)

* ComfyAPI Core v0.0.2

* Respond to PR feedback

* Fix Python 3.9 errors

* Fix missing backward compatibility proxy

* Reorganize types a bit

The input types, input impls, and utility types are now all available in
the versioned API. See the change in `comfy_extras/nodes_video.py` for
an example of their usage.

* Remove the need for `--generate-api-stubs`

* Fix generated stubs differing by Python version

* Fix ruff formatting issues

comfy_api/internal/api_registry.py

@@ -0,0 +1,39 @@
+from typing import Type, List, NamedTuple
+from comfy_api.internal.singleton import ProxiedSingleton
+from packaging import version as packaging_version
+
+
+class ComfyAPIBase(ProxiedSingleton):
+    def __init__(self):
+        pass
+
+
+class ComfyAPIWithVersion(NamedTuple):
+    version: str
+    api_class: Type[ComfyAPIBase]
+
+
+def parse_version(version_str: str) -> packaging_version.Version:
+    """
+    Parses a version string into a packaging_version.Version object.
+    Raises ValueError if the version string is invalid.
+    """
+    if version_str == "latest":
+        return packaging_version.parse("9999999.9999999.9999999")
+    return packaging_version.parse(version_str)
+
+
+registered_versions: List[ComfyAPIWithVersion] = []
+
+
+def register_versions(versions: List[ComfyAPIWithVersion]):
+    versions.sort(key=lambda x: parse_version(x.version))
+    global registered_versions
+    registered_versions = versions
+
+
+def get_all_versions() -> List[ComfyAPIWithVersion]:
+    """
+    Returns a list of all registered ComfyAPI versions.
+    """
+    return registered_versions