This reverts commit e61f485a, reversing
changes made to 00c47d07.

This reverts commit eb819116.

Hide a bunch of debug logging statements in #ifdef SHOW_DEBUG to prevent spinning a mutex in hot paths.

Complete the change from lldiskcache -> llfilesystem and then addition of new lldiskcache implementation

The folder where the disk cache lives was originally renamed from llvfs to llcache but @henri's suggestion that that doesn't reflect the other files in the same place and it should be llfilesystem is a good one so I changed it over

Renamed the references to LLVFile and llvfile.* source code plus cmake scripts to use a different name - lldiskcache - since that more closely resembles what it is (or will be) now that the VFA is no more

First part of change to remove LLVFS from the Viewer. Consists of code changes to remove LLVFS and LLVFSThread classes along with the associated source files. The existing llvfs folder is renamed to llcache. Also includes changes to CMake script in many places to reflect changes. Eventually, llvfile source file and class will be renamed but that is not in this change.