Fix issues identified during PR review by RyanjDick and brandonrising

- ModelMetadataStoreService is now injected into ModelRecordStoreService
  (these two services are really joined at the hip, and should someday be merged)
- ModelRecordStoreService is now injected into ModelManagerService
- Reduced timeout value for the various installer and download wait*() methods
- Introduced a Mock modelmanager for testing
- Removed bare print() statement with _logger in the install helper backend.
- Removed unused code from model loader init file
- Made `locker` a private variable in the `LoadedModel` object.
- Fixed up model merge frontend (will be deprecated anyway!)

invokeai/backend/model_manager/load/__init__.py

@@ -4,10 +4,6 @@ Init file for the model loader.
 """
 from importlib import import_module
 from pathlib import Path
-from typing import Optional
-
-from invokeai.app.services.config import InvokeAIAppConfig
-from invokeai.backend.util.logging import InvokeAILogger
 
 from .convert_cache.convert_cache_default import ModelConvertCache
 from .load_base import AnyModelLoader, LoadedModel
@@ -19,16 +15,3 @@ for module in loaders:
     import_module(f"{__package__}.model_loaders.{module}")
 
 __all__ = ["AnyModelLoader", "LoadedModel", "ModelCache", "ModelConvertCache"]
-
-
-def get_standalone_loader(app_config: Optional[InvokeAIAppConfig]) -> AnyModelLoader:
-    app_config = app_config or InvokeAIAppConfig.get_config()
-    logger = InvokeAILogger.get_logger(config=app_config)
-    return AnyModelLoader(
-        app_config=app_config,
-        logger=logger,
-        ram_cache=ModelCache(
-            logger=logger, max_cache_size=app_config.ram_cache_size, max_vram_cache_size=app_config.vram_cache_size
-        ),
-        convert_cache=ModelConvertCache(app_config.models_convert_cache_path),
-    )

invokeai/backend/model_manager/load/load_base.py

@@ -39,21 +39,21 @@ class LoadedModel:
     """Context manager object that mediates transfer from RAM<->VRAM."""
 
     config: AnyModelConfig
-    locker: ModelLockerBase
+    _locker: ModelLockerBase
 
     def __enter__(self) -> AnyModel:
         """Context entry."""
-        self.locker.lock()
+        self._locker.lock()
         return self.model
 
     def __exit__(self, *args: Any, **kwargs: Any) -> None:
         """Context exit."""
-        self.locker.unlock()
+        self._locker.unlock()
 
     @property
     def model(self) -> AnyModel:
         """Return the model without locking it."""
-        return self.locker.model
+        return self._locker.model
 
 
 class ModelLoaderBase(ABC):

invokeai/backend/model_manager/load/load_default.py

@@ -75,7 +75,7 @@ class ModelLoader(ModelLoaderBase):
 
         model_path = self._convert_if_needed(model_config, model_path, submodel_type)
         locker = self._load_if_needed(model_config, model_path, submodel_type)
-        return LoadedModel(config=model_config, locker=locker)
+        return LoadedModel(config=model_config, _locker=locker)
 
     def _get_model_path(
         self, config: AnyModelConfig, submodel_type: Optional[SubModelType] = None