Readability on Metadata & ExtrinsicSignature (#1314)

* Readbility on Metadata & ExtrinsicSignature

* Version  payload

* Adjust versioning

* De-dup asVx

packages/api-metadata/src/consts/fromMetadata/index.ts

@@ -14,7 +14,7 @@ import { stringCamelCase } from '@polkadot/util';
  * @param metadata - The metadata
  */
 export default function fromMetadata (metadata: Metadata): Constants {
-  return metadata.asV7.modules.reduce((result, moduleMetadata): Constants => {
+  return metadata.asLatest.modules.reduce((result, moduleMetadata): Constants => {
     if (moduleMetadata.constants.isEmpty) {
       return result;
     }