Add cli tool to analyse runner+config combinations and produce a readable summary on compatibility

Summary:
This tool mimics how the e2e_workflow initializes the runner+config pair, which is the only way to obtain the dataset information from the catalog.

This is very early and mostly helps debug. In the near future, this tool is meant to help users understand whether their current setup is compatible with the AIM lineage automation D2 (https://github.com/facebookresearch/d2go/commit/7992f91324aee6ae59795063a007c6837e60cdb8)GO provides, ideally giving clear signal on what to change.

Differential Revision: D32497618

fbshipit-source-id: 83f1d6ae1dca48ce37a05c84b460ea4bb7a1fd79

d2go/runner/__init__.py

@@ -3,15 +3,15 @@
 
 
 import importlib
-from typing import Type, Union
+from typing import Type, Union, Optional
 
 from pytorch_lightning import LightningModule
 
-from .default_runner import BaseRunner, Detectron2GoRunner, GeneralizedRCNNRunner
+from .default_runner import BaseRunner, GeneralizedRCNNRunner
 
 
 def create_runner(
-    class_full_name: str, *args, **kwargs
+    class_full_name: Optional[str], *args, **kwargs
 ) -> Union[BaseRunner, Type[LightningModule]]:
     """Constructs a runner instance if class is a d2go runner. Returns class
     type if class is a Lightning module.