Windows WSL via Registry Persistence

This module will install a payload in WSL and execute it at user
logon or system startup via the registry value in "CurrentVersion\Run"
or "RunOnce" (depending on privilege and selected method).
The payload will be installed completely in registry.

Staged payloads, like fetch payloads in linux X64 don't tend to work. The payload
will ask for the stage, then submit the HTTP fetch request
and when the payload is sent it doesn't execute.

`cmd/linux/http/x64/meterpreter_reverse_tcp` and unix cmd payloads tend to work.