Write event logs to database before transforming

- enables decoupling event extraction/persistence from transformation
- modifies event transformer, converter, and log chunker to accept
  payload that includes internal log database ID with log data
- remove alias for transformer pkg as shared_t
- remove unused mock watcher repository

libraries/shared/transformer/event_transformer.go

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