final tidying before marking PR as ready for review

- Replace AnyModelLoader with ModelLoaderRegistry
- Fix type check errors in multiple files
- Remove apparently unneeded `get_model_config_enum()` method from model manager
- Remove last vestiges of old model manager
- Updated tests and documentation

resolve conflict with seamless.py

invokeai/backend/model_manager/probe.py

@@ -8,7 +8,6 @@ import torch
 from picklescan.scanner import scan_file_path
 
 import invokeai.backend.util.logging as logger
-from .util.model_util import lora_token_vector_length, read_checkpoint_meta
 from invokeai.backend.util.util import SilenceWarnings
 
 from .config import (
@@ -23,6 +22,7 @@ from .config import (
     SchedulerPredictionType,
 )
 from .hash import FastModelHash
+from .util.model_util import lora_token_vector_length, read_checkpoint_meta
 
 CkptType = Dict[str, Any]
 
@@ -53,6 +53,7 @@ LEGACY_CONFIGS: Dict[BaseModelType, Dict[ModelVariantType, Union[str, Dict[Sched
     },
 }
 
+
 class ProbeBase(object):
     """Base class for probes."""