[RFC][DeviceSanitizer][Refactor] Move symbolizer to a standalone lib.

[yingcong-wu]

The symbolizer used in sanitizer layer is sometime built with libc++, and that introduces some unwanted libc++ to ur_loader.so and has caused some problems. This PR aims to make the symbolizer a standalone lib. In this way, we can contain the symbols and make sure them does not affect ur_loader.so in any possible way.

[pbalcer]

introduces some unwanted libc++ to ur_loader.so and has caused some problems

What problems?
This should continue to be linked statically if UR_STATIC_LOADER is set.

[yingcong-wu]

What problems?

The problem is that in some cases the LLVM project will build with libc++ while sycl(and the UR of course) will stick to libstdc++. The sybmolizer would have to be built with libc++ to align with LLVM, which means we would have to link libc++ and libc++abi to ur_loader since the symbolizer implementation is built within it.

And that cause the problem before because libc++abi would have some common (unmangled ones that does not any namespace, e.g. __gxx_personality_v0) symbols exported, and linking it would have the problem that if those symbols are used elsewhere inside ur_loader, in linking stage the linker would prefer the libc++abi ones than libstdc++ ones, which will lead to mismatch problem and runtime failure since other parts of ur_loader are built with libstdc++.

We previously had a PR to mitigate that problem by putting libgcc_s before libc++abi, and that could work (oneapi-src/unified-runtime#2478). However, the problem of introducing libc++/libc++abi/LLVM symbols
to other parts of ur_loader still exists, and the only proper way to contain those symbols is to make symbolizer a standalone dynamic library.

That being said, there is no pressing issue related to this change, we can leave it as is. I am marking this PR an RFC one.