Add sys.get_reg() function to eldritch.

[adm1nPanda]

What type of PR is this?

/kind feature
/kind eldritch-function

What this PR does / why we need it:

Added sys.get_reg() function to eldritch. only installs on windows systems.
$> sys.get_reg("HKEY_LOCAL_MACHINE","SOFTWARE\Microsoft\Windows\CurrentVersion")
{
"ProgramFilesDir": "C:\Program Files",
"CommonFilesDir": "C:\Program Files\Common Files",
"ProgramFilesDir (x86)": "C:\Program Files (x86)",
"CommonFilesDir (x86)": "C:\Program Files (x86)\Common Files",
"CommonW6432Dir": "C:\Program Files\Common Files",
"DevicePath": "%SystemRoot%\inf",
"MediaPathUnexpanded": "%SystemRoot%\Media",
"ProgramFilesPath": "%ProgramFiles%",
"ProgramW6432Dir": "C:\Program Files",
"SM_ConfigureProgramsName": "Set Program Access and Defaults",
"SM_GamesName": "Games"
}

Which issue(s) this PR fixes:

Fixes #358

[codecov]

Codecov Report

Merging #362 (fcae82a) into main (c30f20c) will decrease coverage by 0.23%.
The diff coverage is 57.33%.

@@            Coverage Diff             @@
##             main     #362      +/-   ##
==========================================
- Coverage   75.13%   74.91%   -0.23%     
==========================================
  Files         103      104       +1     
  Lines        6818     6892      +74     
==========================================
+ Hits         5123     5163      +40     
- Misses       1599     1633      +34     
  Partials       96       96              

Files	Coverage Δ
implants/lib/eldritch/src/lib.rs	92.75% <100.00%> (ø)
implants/lib/eldritch/src/sys.rs	49.39% <50.00%> (+0.03%)	⬆️
implants/lib/eldritch/src/sys/get_reg_impl.rs	57.14% <57.14%> (ø)

... and 1 file with indirect coverage changes

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[hulto]

Couple fixes but looks really good. Love the testing 🤌

[hulto]

One more change to remove unwrap but then good to send 🚀