add numeric install version value to windows registry on install

[zackattack01]

This is part 2 towards allowing us to improve our intune setup recommendations. This adds a new InstalledVersionNum registry key and value which is inserted during our MSI installation. This will give a REG_DWORD type version entry for intune configurations to compare against when determining update/reinstallation behavior for new packages, effectively allowing an "upgrade only" type setup.

Installing from an MSI built with these changes yields the following:

PS C:\Users\zack-\code\launcher> Get-ItemProperty 'HKLM:\Software\Kolide\Launcher\Kolide-nababe-k2\InstalledVersionNum'

(default)    : 1011006
PSPath       : Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\Software\Kolide\Launcher\Kolide-nababe-k2\InstalledVersionNum
PSParentPath : Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\Software\Kolide\Launcher\Kolide-nababe-k2
PSChildName  : InstalledVersionNum
PSDrive      : HKLM
PSProvider   : Microsoft.PowerShell.Core\Registry

See the full issue here for additional context.

This is just the installation portion, follow up PRs will include a similar entry to indicate the CurrentVersionNum which will take the autoupdated launcher versions into account, as well as report the value of these entries within flares