refactor: add address codec to core (#15364)

core/address/codec.go

@@ -0,0 +1,9 @@
+package address
+
+// Codec defines an interface to convert addresses from and to string/bytes.
+type Codec interface {
+	// StringToBytes decodes text to bytes
+	StringToBytes(text string) ([]byte, error)
+	// BytesToString encodes bytes to text
+	BytesToString(bz []byte) (string, error)
+}