Implementation of SMB2 headers

[Frky]

Proposal implementation for SMB2 headers dissection.
This implementation is based on the official documentation of SMB2, available here.

Note that implementation is minimalistic and does not handle every part of the protocol.
For instance, some fields have been implemented as bytes, but would deserve a specific Field class, such as the field SystemTime in SMB2_Negociate_Protocol_Response_Header that should be parsing the date format:

class SMB2_Negociate_Protocol_Response_Header(Packet):
    name = "SMB2 Negociate Protocol Response Header"
    fields_desc = [
        XLEShortField("StructureSize", 0),
        ...
        # TODO FIXME
        XLongField("SystemTime", 0),
        ...

[codecov]

Codecov Report

Merging #2629 into master will decrease coverage by 0.37%.
The diff coverage is 95.23%.

@@            Coverage Diff             @@
##           master    #2629      +/-   ##
==========================================
- Coverage   88.61%   88.24%   -0.38%     
==========================================
  Files         247      248       +1     
  Lines       52053    52555     +502     
==========================================
+ Hits        46125    46375     +250     
- Misses       5928     6180     +252     

Impacted Files	Coverage Δ
scapy/config.py	83.78% <ø> (ø)
scapy/fields.py	92.20% <89.58%> (-0.03%)	⬇️
scapy/layers/netbios.py	92.42% <100.00%> (+0.23%)	⬆️
scapy/layers/smb.py	100.00% <100.00%> (ø)
scapy/layers/smb2.py	100.00% <100.00%> (ø)
scapy/packet.py	81.47% <100.00%> (-0.01%)	⬇️
scapy/layers/tls/automaton_srv.py	69.19% <0.00%> (-8.84%)	⬇️
scapy/layers/tls/automaton_cli.py	74.91% <0.00%> (-7.77%)	⬇️
scapy/layers/tls/handshake.py	82.65% <0.00%> (-4.78%)	⬇️
scapy/layers/tls/record_sslv2.py	86.03% <0.00%> (-3.36%)	⬇️
... and 24 more