Samples for loading kernel files

Hi everyone!

I wanted to drive high-level discussions on how the repo should look like via actual code samples. I've taken the liberty of going forward and writing some samples which are pretty much missing from all SDK samples, because each one has chosen one given strategy from the vast array of methods on loading kernel files.

My currently private repo is [here](https://github.com/MathiasMagnus/OpenCL-KernelLoad).

It explores three methods, although I do intend on adding:

- going by compiler defines only without involving symbols or files
- means of embedding kernel code into the executable

There is an orthogonal aspect, which is loading kernel code or some IR / vendor ISA and compiling it offline. Adding the necessary Clang steps to CMake shouldn't be too much.

These first samples immediately touch on an unrelated topic, of how to present utilities from the SDK to the user, however I'll create a separate issue for that.

The issue links the private OpenCL-KernelLoad samples and mentions adding Clang steps to CMake, but names no repository files or tests. Start by reviewing the linked sample approaches and the repository's CMake entry points; done requires an agreed scope for the loading samples and any offline compilation support.

Written by the indexing model from the issue text.