[LLDB][Statistics] Add coreFile to Target stats (#161448)

This patch adds the coreFilePath, if applicable, to the target
statistics for LLDB. My primary motivation here is sanity check user
reports when they say I had an issue with a specific corefile and then
validating it was in fact that specifies corefile, as right now there is
no guaruntee the filename and the process/target name will be the same.

GitOrigin-RevId: c92e24b7d34f20f41a8cd4f8728d608339778b21