feat: added repo export/import streaming methods

internal/application/application.go

@@ -12,11 +12,14 @@ type SpellCaster interface {
 type SpellCommand interface {
 	Add(ctx context.Context, spell models.Spell) error
 	Delete(ctx context.Context, spellName string) error
+	Import(ctx context.Context, ch <-chan models.Spell) error
 }
 
 type SpellQuery interface {
 	Get(ctx context.Context, spellName string) (models.Spell, error)
 	GetMany(ctx context.Context, query models.SearchQuery) ([]models.Spell, error)
+	Count(ctx context.Context) (int, error)
+	Export(ctx context.Context) (<-chan models.Spell, <-chan error, error)
 }
 
 type Application struct {