Decouple log extraction from transformer delegation

- limit missing headers results set to 100 so that extraction doesn't
  excessively block delegation
- wrap checked headers functions in repository struct
- move storage repository to factory, to correspond with event
  repository path
- remove unused files
- reformat sql
- remove line breaks in imports

libraries/shared/transformer/event_transformer.go

@@ -18,13 +18,12 @@ package transformer
 
 import (
 	"github.com/ethereum/go-ethereum/common"
-
 	"github.com/vulcanize/vulcanizedb/pkg/core"
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
 )
 
 type EventTransformer interface {
-	Execute(logs []core.HeaderSyncLog, headerID int64) error
+	Execute(logs []core.HeaderSyncLog) error
 	GetConfig() EventTransformerConfig
 }