BlockNumber, Nonce -> u32 (#1284)

* BlockNumber -> u32

* Interface types extend, not re-use

* Merge master, rebuild

* Merge typo

* Lazy create struct types (extended definitions)

* Cleanup tests for Nonce u32

* Remove polkadot u64 BlockNumber (substrate default)

* Warn on type dup & still clear

* Allow type overrides to work at any point

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

@@ -16,6 +16,6 @@ const consts = fromMetadata(metadata);
 describe('fromMetadata', (): void => {
   it('should return constants with the correct type and value', (): void => {
     expect(consts.democracy.cooloffPeriod).toBeInstanceOf(ClassOf('BlockNumber'));
-    expect(consts.democracy.cooloffPeriod.toHex()).toEqual('0x0000000000062700');
+    expect(consts.democracy.cooloffPeriod.toHex()).toEqual('0x00062700');
   });
 });