Remove ProtoBuf from OTASCIIArmor

Serves no purpose. For more information, see MEP-4: https://github.com/monetas/protocol-docs/pull/124

Remove unused aliases, fix order of methods.
Otto Allmendinger wrote:
>>  
>> -        theData.Assign(pBlob->m_memBuffer.data(),
>> -                       static_cast<uint32_t>(pBlob->m_memBuffer.size()));
>> -        delete[] pData;
>> -        pData = nullptr;
>
> this doesn't do anything when the variable goes out of scope anyway, right?

It's there only for good practice.

Optimizer removes that automatically during compilation.