Pull request #4400: stream_tcp: fix snort crash when processing held packet on flow...

Pull request #4400: stream_tcp: fix snort crash when processing held packet on flow when reassembly policy is IGNORE

Merge in SNORT/snort3 from ~DAVMCPHE/snort3:tcp_reassembly_rewrite_u3.0 to master

Squashed commit of the following:

commit 4aeb81a4548c117b0d5595b03f5d3a4860ee8c0d
Author: davis mcpherson <davmcphe@cisco.com>
Date:   Fri Jul 26 12:37:12 2024 -0400

    stream_tcp: streamline allocation and release of reassemblers, tweak ips flush_on_data process

    stream_tcp: implement ignore flush policy reassembler as a singleton to improve performance,
    implement all TcpReassembler base class public methods as virtual methods and override each in
    the ignore flush policy subclass to do nothing