Remove pre-iterator concepts

- No more IndexRecord/Result/dbGetPage nonsense
 - Queue is just track ids
 - i am so tired and have so much to do

lib/leveldb/include/leveldb/slice.h

@@ -35,6 +35,9 @@ class LEVELDB_EXPORT Slice {
   // Create a slice that refers to the contents of "s"
   Slice(const std::string& s) : data_(s.data()), size_(s.size()) {}
 
+  // Create a slice that refers to the contents of "s"
+  Slice(std::string_view s) : data_(s.data()), size_(s.size()) {}
+
   // Create a slice that refers to s[0,strlen(s)-1]
   Slice(const char* s) : data_(s), size_(strlen(s)) {}