[llvm] [offload][l0] Implement context groups and add actual L0 driver version to info (PR #217562)

[Jan Trusiłło via llvm-commits]

311Volt wrote:

Original revision broke the `khr_get_default_context()` support added in https://github.com/llvm/llvm-project/pull/216863 , so change libsycl to create separate logical SYCL platforms (which share their `ol_platform_handle_t`) for each liboffload context group. Feedback needed from @KseniyaTikhomirova 

https://github.com/llvm/llvm-project/pull/217562