Maybe we should change PacketBufferTLVWriter so we can finalize it

[todo]

connectedhomeip/src/app/CommandSender.h

Lines 248 to 257 in 4711edd

	// TODO Maybe we should change PacketBufferTLVWriter so we can finalize it
	// but have it hold on to the buffer, and get the buffer from it later.
	// Then we could avoid this extra pointer-sized member.
	System::PacketBufferHandle mPendingInvokeData;
	// If mTimedInvokeTimeoutMs has a value, we are expected to do a timed
	// invoke.
	Optional<uint16_t> mTimedInvokeTimeoutMs;
	TLV::TLVType mDataElementContainerType = TLV::kTLVType_NotSpecified;
	bool mSuppressResponse = false;
	bool mTimedRequest = false;

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This issue was generated by todo based on a TODO comment in 4711edd when #12465 was merged. cc @bzbarsky-apple.