Add Windows MSN plugin

[JSCU-CNI]

This PR adds support to dissect for the Windows Live Messenger application. Currently works on WLM 2009 and MSN 7.5 (on Windows 7 and XP), other versions might work too but have not been tested. Artifacts from Messenger Plus! Live are currently not supported.

[Schamper]

:buzzer:

[Schamper]

Don't forget the __init__.py.

Also, messaging vs chat? I assume we will want to use this namespace for applications such as WhatsApp, Signal, IRC, Slack, Teams, etc as well. I think chat is nice and short but I'm not sure what the most commonly used nomenclature would be for these apps.

[JSCU-CNI]

I will leave the naming up to you. We currently use chat with other plugins, but I see no problem in refactoring that internally to what you pick.

[Schamper]

Let's leave it at chat until some zealot comes by and has a strong opinion on it.

[codecov]

Codecov Report

Attention: Patch coverage is 88.40580% with 8 lines in your changes missing coverage. Please review.

Project coverage is 79.17%. Comparing base (e65a678) to head (6882374).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
dissect/target/plugins/apps/chat/msn.py	84.90%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1084      +/-   ##
==========================================
+ Coverage   79.15%   79.17%   +0.02%     
==========================================
  Files         342      344       +2     
  Lines       30281    30350      +69     
==========================================
+ Hits        23968    24029      +61     
- Misses       6313     6321       +8     

Flag	Coverage Δ
unittests	79.17% <88.40%> (+0.02%)	⬆️

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