Move transaction sanitization earlier in the pipeline (#18655)

* Move transaction sanitization earlier in the pipeline

* Renamed HashedTransaction to SanitizedTransaction

* Implement deref for sanitized transaction

* bring back process_transactions test method

* Use sanitized transactions for cost model calculation

sdk/benches/has_duplicates.rs

@@ -0,0 +1,13 @@
+#![feature(test)]
+
+extern crate test;
+use solana_sdk::sanitized_transaction::SanitizedTransaction;
+use test::Bencher;
+
+#[bench]
+fn bench_has_duplicates(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let data = test::black_box([1, 2, 3]);
+        assert!(!SanitizedTransaction::has_duplicates(&data));
+    })
+}