Improve the features of header builder in live customizer

The advantage of building the header in live customizer is that you can have 2 completely different headers for desktop and for mobile. This is not possible when building the header using Elementor. At most, you can only hide certain columns in the responsive setting. This is fine if the layout of your header elements are identical in desktop and mobile but becomes a problem if you need to rearrange header elements. Due to this limitation of Elementor, header builder in the live customiser should include better customization options.