DpGet does not clear out the DpContainer that's passed in

[bocchino]

The DpGet interface requires the user to pass in a reference to a DpContainer. Currently, if that DpContainer has been used in a previous DpGet call, then some of the state from the previous call will remain in the container after the second DpGet call. That shouldn't happen. To support the reuse of DpContainer objects across different calls, this code should fully clear out the DpContainer:

fpp/compiler/tools/fpp-to-cpp/test/component/base/ActiveGetProductsComponentAc.ref.cpp

Lines 3430 to 3441 in e4e137f

	const FwDpIdType baseId = this->getIdBase();
	const FwDpIdType globalId = baseId + containerId;
	const FwSizeType size = DpContainer::getPacketSizeForDataSize(dataSize);
	Fw::Buffer buffer;
	const Fw::Success::T status = this->productGetOut_out(0, globalId, size, buffer);
	if (status == Fw::Success::SUCCESS) {
	container.setId(globalId);
	container.setBuffer(buffer);
	container.setBaseId(baseId);
	container.setPriority(priority);
	}
	return status;

This issue is related to nasa/fprime#2938.