Add more Win32 DPI calls

[Lakritzator]

Extend the functionality in Dapplo.Windows.Dpi a more convenient way to call:

• https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getsystemmetricsfordpi
• https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-systemparametersinfofordpi
• https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-adjustwindowrectexfordpi

So not just the pinvoke with the metrics which returns result.
Place these in DpiApi.cs

Hint: The Enum for the metrics is already available as Dapplo.Windows.User32.Enums.SystemMetric but some metrics have specific results which are also an enum.

Consider other Windows DPI relevant things...