Fix parent record locks usage in child banks (#4159)

* Introduce record locks on txs that will be recorded

* Add tests for LockedAccountsResults

* Fix broken bench

* Exit process_entries on detecting conflicting locks within same entry

runtime/benches/append_vec.rs

@@ -99,6 +99,9 @@ fn append_vec_concurrent_read_append(bencher: &mut Bencher) {
     let indexes1 = indexes.clone();
     spawn(move || loop {
         let len = indexes1.lock().unwrap().len();
+        if len == 0 {
+            continue;
+        }
         let random_index: usize = thread_rng().gen_range(0, len + 1);
         let (sample, pos) = indexes1
             .lock()