refactor: creating image process to handle processing of images

Decoupling this from the DB, it's a good step.

Not yet perfect however.

backend/models/image.go

@@ -160,6 +160,28 @@ func (m ImageModel) FinishProcessing(ctx context.Context, imageId uuid.UUID) (mo
 	return userImage, err
 }
 
+func (m ImageModel) GetImageToProcessID(ctx context.Context, imageID uuid.UUID) (uuid.UUID, error) {
+	getImageToProcessIDStmt := UserImagesToProcess.
+		SELECT(UserImagesToProcess.ID).
+		WHERE(UserImagesToProcess.ImageID.EQ(UUID(imageID)))
+
+	imageToProcess := model.UserImagesToProcess{}
+	err := getImageToProcessIDStmt.QueryContext(ctx, m.dbPool, &imageToProcess)
+
+	return imageToProcess.ID, err
+}
+
+func (m ImageModel) SetNotStarted(ctx context.Context, processingImageId uuid.UUID) error {
+	startProcessingStmt := UserImagesToProcess.
+		UPDATE(UserImagesToProcess.Status).
+		SET(model.Progress_NotStarted).
+		WHERE(UserImagesToProcess.ID.EQ(UUID(processingImageId)))
+
+	_, err := startProcessingStmt.ExecContext(ctx, m.dbPool)
+
+	return err
+}
+
 func (m ImageModel) StartProcessing(ctx context.Context, processingImageId uuid.UUID) error {
 	startProcessingStmt := UserImagesToProcess.
 		UPDATE(UserImagesToProcess.Status).