[Hinty] Core typing: windows

[gpotter2]

It's been a long time since I've done one of those.

• Core typing of Windows
• Change the mypy CI to test Linux AND Windows independently
• bunch of fixes everywhere, especially inconsistencies with the use of NetworkInterface or str in routes, that were sometimes messed up (but it worked because NetworkInterface can act as a string for backward compatibility)

[codecov[bot]]

Codecov Report

Merging #3684 (101d3cf) into master (eef49d5) will decrease coverage by 0.08%. The diff coverage is 43.60%.

@@            Coverage Diff             @@
##           master    #3684      +/-   ##
==========================================
- Coverage   86.11%   86.03%   -0.09%     
==========================================
  Files         296      299       +3     
  Lines       67290    68029     +739     
==========================================
+ Hits        57948    58528     +580     
- Misses       9342     9501     +159     

Impacted Files	Coverage Δ
scapy/arch/linux.py	0.73% <0.00%> (-0.01%)	:arrow_down:
scapy/base_classes.py	77.81% <0.00%> (ø)
scapy/config.py	80.55% <0.00%> (-0.15%)	:arrow_down:
scapy/utils.py	77.21% <0.00%> (-0.07%)	:arrow_down:
scapy/supersocket.py	58.38% <3.38%> (-1.98%)	:arrow_down:
scapy/layers/inet6.py	88.01% <25.00%> (-0.22%)	:arrow_down:
scapy/automaton.py	74.04% <50.00%> (-0.31%)	:arrow_down:
scapy/arch/__init__.py	72.54% <62.50%> (-3.54%)	:arrow_down:
scapy/arch/libpcap.py	68.24% <72.72%> (-1.15%)	:arrow_down:
scapy/arch/windows/__init__.py	67.16% <77.08%> (-1.14%)	:arrow_down:
... and 46 more

[gpotter2]

@guedou @p-l- This is ready for review. This is pretty interesting IMHO because it uses mypy's ability to specify the platform.