[lldb] Remove FileSystem::Initialize from FileCollector

This patch removes the ability to instantiate the LLDB FileSystem class
with a FileCollector. It keeps the ability to collect files, but uses
the FileCollectorFileSystem to do that transparently.

Because the two are intertwined, this patch also removes the
finalization logic which copied the files over out of process.

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp

@@ -2723,7 +2723,6 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
   } else {
     FileSpec module_file(pathname);
     FileSystem::Instance().Resolve(module_file);
-    FileSystem::Instance().Collect(module_file);
 
     fs::file_status st;
     std::error_code ec = status(module_file.GetPath(), st);