Pull request #4240: stream_tcp: Refactor tcp overlap, segment list and reassembly...

Pull request #4240: stream_tcp: Refactor tcp overlap, segment list and reassembly classes to improve class structure and relationships

Merge in SNORT/snort3 from ~DAVMCPHE/snort3:reassembly_rewrite_u2.0 to master

Squashed commit of the following:

commit 6e4456f7895584520a5e6bb2d3eae0458b33d516
Author: davis mcpherson <davmcphe@cisco.com>
Date:   Thu Feb 22 11:44:08 2024 -0500

    stream_tcp: initial refactor to move alert functions to their own class

    stream_tcp: refactor to move tcp overlap processing out of reassembly class

    stream_tcp: merge TcpStreamSession into TcpSession

    stream_tcp: refactor segment nodes to implement reassembly cursor and
    eliminate tracking variables such as c_seq/c_len, etc. add helper functions
    to track state

    stream_tcp: improve variable and function names for overlap processing

    stream_tcp: refactor TcpReassembler into a virtual base class and subclasses for each mode: ignore, IPS and IDS

    stream: refactor paf logic into a c++ class

    stream_tcp: integrate and streamline setting of flush policy and splitter
                improve tracking of rcv_nxt state

    stream_tcp: delete lws_init, it was redundant with tcp_init; delete FIXITs that are no longer relevant
    stream_tcp: updates from PR review comments