Ports base::win:OSInfo from Chrome to rtc_win in WebRTC.

Enables us to do stuff like:

TEST(WindowsVersion, GetVersionGlobalScopeAccessor) {
  if (GetVersion() < VERSION_WIN10) {
    MethodNotSupportedOnWin10AndLater();
  } else {
    MethodSupportedOnWin10AndLater();
  }
}

which is useful when working with Windows.

Note that, I also port a limited part of base::win::RegKey but only
those parts that are needed to implement OSInfo. Hence, I don't expose
any RegKey APIs.

NOTRY=TRUE

No-Presubmit: True
Bug: webrtc:9265
Change-Id: Ia2fc0963f24044ffaad954aa21d28df9c32b3ee7
Reviewed-on: https://webrtc-review.googlesource.com/77723
Commit-Queue: Henrik Andreassson <henrika@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23326}