[examples] Adding core_high_dpi example

[marler8997]

This example enables HIGHDPI and renders a scale showing how the logical size compares to the pixel size of the window.

[raysan5]

@marler8997 Would you mind renaming the example to core_high_dpi, all raylib examples follow at-least-3-words pattern on their names. Also, the example should be added to the VS2022 solution. Here the example contribution details: https://github.com/raysan5/raylib/blob/master/examples/examples_template.c

[marler8997]

Ok, updated the name and added to the VS project. I don't have VS to test it so hopefully the CI covers it?

[raysan5]

@marler8997 thanks for the addition! 😄