Port sigverify to identify and mark simple vote transaction to v1.7 (#20147)

* sigverify to identify and mark simple vote transaction (#20021)

* check vote tx at get_packet_offsets to cover both cpu and gpu paths

* add pubkey_len to PacketOffsets to reduce the redundant bytes counting

* allow vote to have 1 or 2 sigs (#20082)

sdk/src/packet.rs

@@ -25,6 +25,7 @@ pub struct Meta {
     pub seed: [u8; 32],
     pub slot: Slot,
     pub is_tracer_tx: bool,
+    pub is_simple_vote_tx: bool,
 }
 
 #[derive(Clone)]