refactor: backend/service split, channel-based llm flow (#1963)

Refactor: channel based llm flow and services split

---------

Signed-off-by: Dave Lee <dave@gray101.com>

core/state.go

@@ -0,0 +1,41 @@
+package core
+
+import (
+	"github.com/go-skynet/LocalAI/core/backend"
+	"github.com/go-skynet/LocalAI/core/config"
+	"github.com/go-skynet/LocalAI/core/services"
+	"github.com/go-skynet/LocalAI/pkg/model"
+)
+
+// TODO: Can I come up with a better name or location for this?
+// The purpose of this structure is to hold pointers to all initialized services, to make plumbing easy
+// Perhaps a proper DI system is worth it in the future, but for now keep things simple.
+type Application struct {
+
+	// Application-Level Config
+	ApplicationConfig *config.ApplicationConfig
+	// ApplicationState *ApplicationState
+
+	// Core Low-Level Services
+	BackendConfigLoader *config.BackendConfigLoader
+	ModelLoader         *model.ModelLoader
+
+	// Backend Services
+	EmbeddingsBackendService      *backend.EmbeddingsBackendService
+	ImageGenerationBackendService *backend.ImageGenerationBackendService
+	LLMBackendService             *backend.LLMBackendService
+	TranscriptionBackendService   *backend.TranscriptionBackendService
+	TextToSpeechBackendService    *backend.TextToSpeechBackendService
+
+	// LocalAI System Services
+	BackendMonitorService *services.BackendMonitorService
+	GalleryService        *services.GalleryService
+	ListModelsService     *services.ListModelsService
+	LocalAIMetricsService *services.LocalAIMetricsService
+	OpenAIService         *services.OpenAIService
+}
+
+// TODO [NEXT PR?]: Break up ApplicationConfig.
+// Migrate over stuff that is not set via config at all - especially runtime stuff
+type ApplicationState struct {
+}