🎨 Introduce contextualized logging

This commit is multi-fold as it also refactors internally context and logger
as interfaces so it is easier to plug luet as a library externally.

Introduces a garbage collector (related to #227) but doesn't handle yet
parallelism.

Closes #265

pkg/installer/client/local_test.go

@@ -20,7 +20,7 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/mudler/luet/pkg/api/core/types"
+	"github.com/mudler/luet/pkg/api/core/context"
 	"github.com/mudler/luet/pkg/api/core/types/artifact"
 	fileHelper "github.com/mudler/luet/pkg/helpers/file"
 	. "github.com/mudler/luet/pkg/installer/client"
@@ -30,7 +30,7 @@ import (
 
 var _ = Describe("Local client", func() {
 	Context("With repository", func() {
-		ctx := types.NewContext()
+		ctx := context.NewContext()
 
 		It("Downloads single files", func() {
 			tmpdir, err := ioutil.TempDir("", "test")