Change getattr and statx to bespoke policies

* Provides: slight improvement in performance as it no longer will
need to find and then act on the files.
* It doesn't make sense to support all original policy types. Most
people used 'newest' or 'ff' and 'combine' is a better default which
has same runtime as 'newest' but with better output.

src/func_getattr_ff.cpp

@@ -0,0 +1,41 @@
+#include "func_getattr_ff.hpp"
+
+#include "fs_stat.hpp"
+#include "fs_inode.hpp"
+#include "symlinkify.hpp"
+
+
+std::string_view
+Func2::GetAttrFF::name() const
+{
+  return "ff";
+}
+
+int
+Func2::GetAttrFF::operator()(const Branches  &branches_,
+                             const fs::path  &fusepath_,
+                             struct stat     *st_,
+                             const FollowSymlinksEnum follow_symlinks_,
+                             const s64 symlinkify_timeout_)
+{
+  int rv;
+  fs::path fullpath;
+
+  for(const auto &branch : branches_)
+    {
+      fullpath = branch.path / fusepath_;
+      rv = fs::stat(fullpath,st_,follow_symlinks_);
+      if(rv < 0)
+        continue;
+
+      symlinkify::convert_if_can_be_symlink(fullpath,
+                                            st_,
+                                            symlinkify_timeout_);
+
+      fs::inode::calc(branch.path,fusepath_,st_);
+
+      return rv;
+    }
+
+  return -ENOENT;
+}