JSON schema validation not called for RecordsWrite

[thehenrytsai]

It appears that JSON schema validation function (Message.validateJsonSchema(message);) is not invoked by RecordsWrite interface class. The schema validation must be invoked in parse() path to ensure message validity, but should probably also be called in message() path too for sanity to make sure we always return a valid message.

Also in create() we should probably call the unauthorized/unidentified version of the schema.

Wrote a test to sanity verify, and the function is not called:

    it('should invoke JSON schema validation when parsing a RecordsWrite', async () => {
      const alice = await TestDataGenerator.generatePersona();

      const recordsWrite = await RecordsWrite.create({
        signer     : Jws.createSigner(alice),
        dataFormat : 'application/octet-stream',
        data       : TestDataGenerator.randomBytes(10),
      });

      const validateJsonSchemaSpy = Sinon.spy(Message, 'validateJsonSchema');

      await RecordsWrite.parse(recordsWrite.message);

      expect(validateJsonSchemaSpy.called).to.be.true;
    });