Reset index in loop to restart member search (#16955)

## Description

Found from audit, we need to reset the start of the loop when looking
for members

## Test Plan

Added unit test

---
If your changes are not user-facing and do not break anything, you can
skip the following section. Otherwise, please briefly describe what has
changed under the Release Notes section.

### Type of Change (Check all that apply)

- [ ] protocol change
- [ ] user-visible impact
- [ ] breaking change for a client SDKs
- [ ] breaking change for FNs (FN binary must upgrade)
- [ ] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes

crates/sui-framework/docs/bridge/committee.md

@@ -620,6 +620,7 @@ title: Module `0xb::committee`
                 member.blocklisted = blocklisted;
                 pub_keys.push_back(*pub_key);
                 found = <b>true</b>;
+                member_idx = 0;
                 <b>break</b>
             };
 

crates/sui-framework/packages/bridge/sources/committee.move

@@ -267,6 +267,7 @@ module bridge::committee {
                     member.blocklisted = blocklisted;
                     pub_keys.push_back(*pub_key);
                     found = true;
+                    member_idx = 0;
                     break
                 };
 
@@ -680,6 +681,16 @@ module bridge::committee {
         let blocklist = message::extract_blocklist_payload(&blocklist);
         execute_blocklist(&mut committee, blocklist);
 
+        // Blocklist both reverse order
+        let blocklist = message::create_blocklist_message(
+            chain_ids::sui_testnet(),
+            0, // seq
+            0, // type 0 is blocklist
+            vector[eth_address1, eth_address0]
+        );
+        let blocklist = message::extract_blocklist_payload(&blocklist);
+        execute_blocklist(&mut committee, blocklist);
+
         // val 0 is blocklisted
         let (_, blocked_member) = vec_map::get_entry_by_idx(&committee.members, 0);
         assert!(blocked_member.blocklisted, 0);