[SYCL] Implement eviction for in-memory program cache

[uditagarwal97]

Fixes: CMPLRLLVM-27640, #2517

The PR implements LRU cache eviction policy for in-memory program caches.
The high-level idea is to store programs in a linked-list, called eviction list. When the program is first added to the cache, it is also added to the eviction list. When a program is fetched from cache, we move the program to the end of the eviction list. So, that the programs at the beginning of the eviction list are always least recently used.
When adding a new program to cache, we check if the size of the program cache exceeds the threshold, if so, we evict the program from cache and corresponding kernels from Kernel and fast kernel cache.

This PR also adds a new environment variable, SYCL_IN_MEM_CACHE_EVICTION_THRESHOLD that user can use to control the size of in-memory cache. By default, cache eviction is disabled.

[uditagarwal97]

@maarquitos14 Since your last review, I have also converted the E2E test case that I added earlier into unit tests and fixed a few data races.

[keryell]

It took me some time to understand which program it was.
While you are on it, could you please add some top-comments to sycl/source/detail/kernel_program_cache.hpp to give an idea of what it is about?

[maarquitos14]

LGTM.

[uditagarwal97]

@intel/dpcpp-doc-reviewers / @steffenlarsen gentle ping.

[steffenlarsen]

LGTM!

[uditagarwal97]

@intel/llvm-gatekeepers the PR is ready to be merged.