Update slashing protection interchange to v5 (#1816)

## Proposed Changes

Update the slashing protection interchange format to v5 in preparation for finalisation as part of an EIP.

Also, add some more tests and update the commit hash for https://github.com/eth2-clients/slashing-protection-interchange-tests to include the new generated tests.

validator_client/slashing_protection/src/slashing_database.rs

@@ -1,6 +1,6 @@
 use crate::interchange::{
-    CompleteInterchangeData, Interchange, InterchangeFormat, InterchangeMetadata,
-    SignedAttestation as InterchangeAttestation, SignedBlock as InterchangeBlock,
+    Interchange, InterchangeData, InterchangeMetadata, SignedAttestation as InterchangeAttestation,
+    SignedBlock as InterchangeBlock,
 };
 use crate::signed_attestation::InvalidAttestation;
 use crate::signed_block::InvalidBlock;
@@ -25,7 +25,7 @@ pub const CONNECTION_TIMEOUT: Duration = Duration::from_secs(5);
 pub const CONNECTION_TIMEOUT: Duration = Duration::from_millis(100);
 
 /// Supported version of the interchange format.
-pub const SUPPORTED_INTERCHANGE_FORMAT_VERSION: u64 = 4;
+pub const SUPPORTED_INTERCHANGE_FORMAT_VERSION: u64 = 5;
 
 #[derive(Debug, Clone)]
 pub struct SlashingDatabase {
@@ -673,7 +673,6 @@ impl SlashingDatabase {
         .collect::<Result<_, InterchangeError>>()?;
 
         let metadata = InterchangeMetadata {
-            interchange_format: InterchangeFormat::Complete,
             interchange_format_version: SUPPORTED_INTERCHANGE_FORMAT_VERSION,
             genesis_validators_root,
         };
@@ -681,7 +680,7 @@ impl SlashingDatabase {
         let data = data
             .into_iter()
             .map(|(pubkey, (signed_blocks, signed_attestations))| {
-                Ok(CompleteInterchangeData {
+                Ok(InterchangeData {
                     pubkey: pubkey.parse().map_err(InterchangeError::InvalidPubkey)?,
                     signed_blocks,
                     signed_attestations,