[WIP] Optimize TCP read implementation for backpressure handling

[Copilot]

• Explore repository structure and understand codebase
• Run existing tests to verify current state
• Add ordered_packets field to TCB struct
• Modify consume_unordered_packets to move data to ordered_packets
• Update get_recv_window to account for ordered packets
• Modify AsyncRead implementation to read from ordered_packets directly
• Remove channel-based data flow (data_tx/data_rx)
• Update tests to verify new behavior
• Run all tests to ensure no regressions

Original prompt

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This section details on the original issue you should resolve

<issue_title>TCP Read Optimization</issue_title>
<issue_description>The current implementation shares contiguous bytes with an AsyncRead consumer through a channel. However, this approach prevents backpressure, which leads to significant memory consumption if the sending rate is too fast. Furthermore, because the buffered data is immediately sent to the channel, the TCP receive window does not shrink. This disables TCP-level flow control, further exacerbating memory accumulation.

The solution I've come up with is to create an ordered list of packets within the TCB. The consumption method, each time it's called, will move the contiguous packets into this list.
The window calculation will also be modified to determine the actual window size by accounting for the sizes of both the in-order (ordered) and out-of-order packets.
Then, in the AsyncRead implementation, it will get the TCB, pop the first packet from the ordered collection, and write it into the read buffer.</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #74

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