Contribute highgui module dummy implementation

[mkostin]

highgui module contains API for quick UI prototyping. It is also a dependency for tests contribution:

• local - #43
• itseez - #4064

This contribution is aiming to provide dummy implementation that would allow test run on winrt avoiding numerous macro-wrappers disabling highgui dependent code. That should unblock tests contribution referred above.

Subsequent contribution should actually enable highgui related logic for WinRT.

• Added dummy highgui WinRT implementation: 7810fda89b533bd47a6ae7247762f7b210d6701a

Related PR: #4090

[mkostin]

Merged, closing.