Backfill data columns (#15580)

**What type of PR is this?**

Feature

**What does this PR do? Why is it needed?**

Adds data column support to backfill.

**Acknowledgements**

- [x] I have read
[CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
- [x] I have included a uniquely named [changelog fragment
file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
- [x] I have added a description to this PR with sufficient context for
reviewers to understand this PR.

---------

Co-authored-by: Kasey <kasey@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Preston Van Loon <preston@pvl.dev>

beacon-chain/sync/initial-sync/service_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
 	mock "github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/das"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/db/kv"
 	dbtest "github.com/OffchainLabs/prysm/v7/beacon-chain/db/testing"
@@ -152,10 +153,7 @@ func TestService_InitStartStop(t *testing.T) {
 
 	p := p2ptest.NewTestP2P(t)
 	connectPeers(t, p, []*peerData{}, p.Peers())
-	for i, tt := range tests {
-		if i == 0 {
-			continue
-		}
+	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			defer hook.Reset()
 			ctx, cancel := context.WithCancel(t.Context())
@@ -175,6 +173,8 @@ func TestService_InitStartStop(t *testing.T) {
 				InitialSyncComplete: make(chan struct{}),
 			})
 			s.verifierWaiter = verification.NewInitializerWaiter(gs, nil, nil, nil)
+
+			s.blobRetentionChecker = func(primitives.Slot) bool { return true }
 			time.Sleep(500 * time.Millisecond)
 			assert.NotNil(t, s)
 			if tt.setGenesis != nil {
@@ -207,15 +207,22 @@ func TestService_waitForStateInitialization(t *testing.T) {
 		cs := startup.NewClockSynchronizer()
 		ctx, cancel := context.WithCancel(ctx)
 		s := &Service{
-			cfg:          &Config{Chain: mc, StateNotifier: mc.StateNotifier(), ClockWaiter: cs, InitialSyncComplete: make(chan struct{})},
-			ctx:          ctx,
-			cancel:       cancel,
-			synced:       abool.New(),
-			chainStarted: abool.New(),
-			counter:      ratecounter.NewRateCounter(counterSeconds * time.Second),
-			genesisChan:  make(chan time.Time),
+			cfg:                  &Config{Chain: mc, StateNotifier: mc.StateNotifier(), ClockWaiter: cs, InitialSyncComplete: make(chan struct{})},
+			ctx:                  ctx,
+			cancel:               cancel,
+			synced:               abool.New(),
+			chainStarted:         abool.New(),
+			counter:              ratecounter.NewRateCounter(counterSeconds * time.Second),
+			genesisChan:          make(chan time.Time),
+			blobRetentionChecker: func(primitives.Slot) bool { return true },
 		}
 		s.verifierWaiter = verification.NewInitializerWaiter(cs, nil, nil, nil)
+		syWait := func() (das.SyncNeeds, error) {
+			clock, err := cs.WaitForClock(ctx)
+			require.NoError(t, err)
+			return das.NewSyncNeeds(clock.CurrentSlot, nil, primitives.Epoch(0))
+		}
+		s.cfg.SyncNeedsWaiter = syWait
 		return s, cs
 	}
 
@@ -225,6 +232,7 @@ func TestService_waitForStateInitialization(t *testing.T) {
 		defer cancel()
 
 		s, _ := newService(ctx, &mock.ChainService{Genesis: time.Now(), ValidatorsRoot: [32]byte{}})
+		s.blobRetentionChecker = func(primitives.Slot) bool { return true }
 		wg := &sync.WaitGroup{}
 		wg.Go(func() {
 			s.Start()
@@ -252,6 +260,7 @@ func TestService_waitForStateInitialization(t *testing.T) {
 		require.NoError(t, err)
 		gt := st.GenesisTime()
 		s, gs := newService(ctx, &mock.ChainService{State: st, Genesis: gt, ValidatorsRoot: [32]byte{}})
+		s.blobRetentionChecker = func(primitives.Slot) bool { return true }
 
 		expectedGenesisTime := gt
 		wg := &sync.WaitGroup{}