feat(store/v2): implement the feature to upgrade the store keys (#20453)

Co-authored-by: Matt Kocubinski <mkocubinski@gmail.com>

core/store/upgrade.go

@@ -2,17 +2,8 @@ package store
 
 // StoreUpgrades defines a series of transformations to apply the multistore db upon load
 type StoreUpgrades struct {
-	Added   []string      `json:"added"`
-	Renamed []StoreRename `json:"renamed"`
-	Deleted []string      `json:"deleted"`
-}
-
-// StoreRename defines a name change of a sub-store.
-// All data previously under a PrefixStore with OldKey will be copied
-// to a PrefixStore with NewKey, then deleted from OldKey store.
-type StoreRename struct {
-	OldKey string `json:"old_key"`
-	NewKey string `json:"new_key"`
+	Added   []string `json:"added"`
+	Deleted []string `json:"deleted"`
 }
 
 // IsAdded returns true if the given key should be added
@@ -40,17 +31,3 @@ func (s *StoreUpgrades) IsDeleted(key string) bool {
 	}
 	return false
 }
-
-// RenamedFrom returns the oldKey if it was renamed
-// Returns "" if it was not renamed
-func (s *StoreUpgrades) RenamedFrom(key string) string {
-	if s == nil {
-		return ""
-	}
-	for _, re := range s.Renamed {
-		if re.NewKey == key {
-			return re.OldKey
-		}
-	}
-	return ""
-}