Handle the installation of shader files for GPU commands

[daljit46]

With the merging of #3238, we gained the capability of running compute shaders written in Slang via WebGPU. One important issue that we didn't deal with is the installation of shader files during the install phase of CMake. Current an executable that makes use of the API will look into a shaders folder where the executable is located (which was made possible due to #3218). A more robust strategy should be devised. One possibility would be to copy the required shader files into installation_dir/lib and then instruct the GPU API to look for the shader files in ../lib by default.