Add GLES 3.0 compatible polydata mapper

Addresses #18788

This mapper derives vtkOpenGLPolyDataMapper and reimplements a subset of features in order to be compatible with WebGL 2 (OpenGL ES 3.0) contexts. vtkOpenGLES30PolyDataMapper overrides vtkPolyDataMapper when VTK is built for OpenGL ES. The composite poly data mapper has been slightly adapted to derive the new gles mapper or desktop gl mapper based on the OpenGL version at compile time. This work helps the WebAssembly cause as WebGL2 (OpenGL ES 3.0) is used in the browser.

The first commit enforces an ES 3.0 context in the x11 render window. I found that it's a good configuration for tests/examples.