feat(wm): make active border with configurable

This commit introduces a new command which lets the user set a custom
width value for the active window border when it is enabled.

Unfortunately a little more width is required when working with rounded
windows on Windows 11 to fill the gap left by the rounding. The default
width remains set at 20.

re #232

komorebi-core/src/lib.rs

@@ -105,6 +105,7 @@ pub enum SocketMessage {
     CompleteConfiguration,
     ActiveWindowBorder(bool),
     ActiveWindowBorderColour(WindowKind, u32, u32, u32),
+    ActiveWindowBorderWidth(i32),
     InvisibleBorders(Rect),
     WorkAreaOffset(Rect),
     MonitorWorkAreaOffset(usize, Rect),