Use "outer" positions in all window-related operations

[hecrj]

See https://docs.rs/winit/latest/winit/window/struct.WindowAttributes.html#method.with_position.

I think this is the best we can do until rust-windowing/winit#2645 is addressed.

[SoulSharer]

Thanks for the fix! We also need to correct comments for window events:

core\src\window\event.rs:

  /// A window was opened.
    Opened {
        /// The position of the opened window. This is relative to the top-left corner of the desktop
        /// the window is on, including virtual desktops. Refers to window's "outer" position,
        /// or the window area, in logical pixels.
        ///
        /// **Note**: Not available in Wayland.
        position: Option<Point>,
        /// The size of the created window. This is its "inner" size, or the size of the
        /// client area, in logical pixels.
        size: Size,
    },

Now I'm also wondering whether we should provide "outer" size for Opened event.