Missing support for double precision vertex attributes

[simeonkr]

According to https://registry.khronos.org/OpenGL-Refpages/gl4/html/glVertexAttribPointer.xhtml, vertex attributes that have a double precision type (double, dvec2, etc.) must be specified using glVertexAttribLPointer. However, the internal
setVertexAttribPointer makes use of only glVertexAttribPointer and glVertexAttribIPointer, which means that precision will be lost even if the VertexArrayDescriptor argument specifies a Double type. In fact, I found that redefining vertex attributes to be double precision (making sure to pass in the correct type to vertexAttribPointer) makes otherwise functioning code result in black screens.