Improve status bar resize handling

[ozone10]

ref #14959

[donho]

@ozone10
By "Improve status bar resize handling", it improves the status improvement display or it's a code refactoring?

[ozone10]

@donho
technically it's more code refactoring. But it helps in some rare case to avoid visual glitch (status bar not repositioning immediately) when changing between full and less mode.

Instead of relying on SetWindowPos we send WM_SIZE directly to status bar.