Refactor API frame helpers to enable buffer reuse (#8825)

esphome/components/api/api_connection.cpp

@@ -1962,7 +1962,7 @@ bool APIConnection::send_buffer(ProtoWriteBuffer buffer, uint32_t message_type)
     }
   }
 
-  APIError err = this->helper_->write_packet(message_type, buffer.get_buffer()->data(), buffer.get_buffer()->size());
+  APIError err = this->helper_->write_protobuf_packet(message_type, buffer);
   if (err == APIError::WOULD_BLOCK)
     return false;
   if (err != APIError::OK) {