Update is_available check to support PeerDAS. (#6076)

* Update `is_available` check to support PeerDAS.

* Merge branch 'unstable' into da-checker-das

# Conflicts:
#	beacon_node/beacon_chain/src/data_availability_checker.rs
#	beacon_node/beacon_chain/src/data_availability_checker/overflow_lru_cache.rs

* Simplify code using `map_or`

* Merge branch 'unstable' into da-checker-das

# Conflicts:
#	consensus/types/src/chain_spec.rs

* Remove `epoch` method from `PendingComponents`

* Add `put_kzg_verified_data_columns` method.

consensus/types/src/blob_sidecar.rs

@@ -1,7 +1,7 @@
 use crate::test_utils::TestRandom;
 use crate::{
     beacon_block_body::BLOB_KZG_COMMITMENTS_INDEX, BeaconBlockHeader, BeaconStateError, Blob,
-    EthSpec, FixedVector, Hash256, SignedBeaconBlockHeader, Slot, VariableList,
+    Epoch, EthSpec, FixedVector, Hash256, SignedBeaconBlockHeader, Slot, VariableList,
 };
 use crate::{KzgProofs, SignedBeaconBlock};
 use bls::Signature;
@@ -160,6 +160,13 @@ impl<E: EthSpec> BlobSidecar<E> {
         self.signed_block_header.message.slot
     }
 
+    pub fn epoch(&self) -> Epoch {
+        self.signed_block_header
+            .message
+            .slot
+            .epoch(E::slots_per_epoch())
+    }
+
     pub fn block_root(&self) -> Hash256 {
         self.signed_block_header.message.tree_hash_root()
     }