Support new _WindowsBuildVersion dependency type

[jantari]

I had seen that a new way for packages to specify a Windows version they are or aren't supported on was likely coming in the ThinInstaller changelog:

New in 2020-09-29 release
==========================
1. Use an internal method to detect Win10 build version.
[..]

but I hadn't seen any examples of what that will look like in the wild until now.

Package https://download.lenovo.com/pccbbs/mobiles/n1fup90w_2_.xml declares a _WindowsBuildVersion dependency.

Previously, windows version detection was done by an _ExternalDetection node and separate executables,
so this is a long overdue improvement imo and should be easy to add support for in LSUClient.