Auto-detect llvm symbolizer path when LLVM_SYMBOLIZER_PATH is not set

[tevoinea]

There are common paths we can check where the llvm symbolizer can be found, as well as ways to find it for example which llvm-symbolizer on linux. Setting the LLVM_SYMBOLIZER_PATH environment variable should always take precedent in case a user has multiple versions installed and they want to use a particular one.

AB#167338