Optimize sniff's offline

[gpotter2]

This PR contains optimizations to sniff's offline regarding:

• iterables with filters (we now do not write them down to a temporary file just to read them again) but instead directly write them to tcpdump
• detection of packet lists (we now do not iterate through the whole packet list to check that it is indeed a packet list)

It introduces in this regard the IterSocket util which acts like a SuperSocket over an iterator.

fixes #3053

[codecov]

Codecov Report

Merging #3055 (73055ea) into master (ef4937f) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3055      +/-   ##
==========================================
- Coverage   85.36%   85.34%   -0.02%     
==========================================
  Files         256      256              
  Lines       54135    54178      +43     
==========================================
+ Hits        46210    46240      +30     
- Misses       7925     7938      +13     

Impacted Files	Coverage Δ
scapy/sendrecv.py	84.55% <100.00%> (+0.08%)	⬆️
scapy/supersocket.py	60.18% <100.00%> (+4.36%)	⬆️
scapy/utils.py	78.10% <100.00%> (-0.61%)	⬇️
scapy/contrib/loraphy2wan.py	97.32% <0.00%> (-1.28%)	⬇️
scapy/arch/windows/__init__.py	67.73% <0.00%> (-0.57%)	⬇️
scapy/config.py	81.29% <0.00%> (-0.20%)	⬇️
scapy/contrib/bgp.py	91.69% <0.00%> (-0.17%)	⬇️
scapy/fields.py	91.20% <0.00%> (ø)
scapy/layers/tls/automaton_cli.py	70.96% <0.00%> (+0.13%)	⬆️

[gpotter2]

This is ready for review. Should be pretty straightforward
@guedou @p-l-