Add support for larger transactions in Raft (#24991)

* Add support for larger transactions in Raft

* Add CHANGELOG

* Appease the new lint rules

sdk/physical/encoding_test.go

@@ -0,0 +1,51 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package physical
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestTransactionalStorageEncoding_TransactionLimits(t *testing.T) {
+	tc := []struct {
+		name        string
+		be          Backend
+		wantEntries int
+		wantSize    int
+	}{
+		{
+			name: "non-transactionlimits backend",
+			be:   &TestTransactionalNonLimitBackend{},
+
+			// Should return zeros to let the implementor choose defaults.
+			wantEntries: 0,
+			wantSize:    0,
+		},
+		{
+			name: "transactionlimits backend",
+			be: &TestTransactionalLimitBackend{
+				MaxEntries: 123,
+				MaxSize:    345,
+			},
+
+			// Should return underlying limits
+			wantEntries: 123,
+			wantSize:    345,
+		},
+	}
+
+	for _, tt := range tc {
+		t.Run(tt.name, func(t *testing.T) {
+			be := NewStorageEncoding(tt.be).(TransactionalLimits)
+
+			// Call the TransactionLimits method
+			maxEntries, maxBytes := be.TransactionLimits()
+
+			require.Equal(t, tt.wantEntries, maxEntries)
+			require.Equal(t, tt.wantSize, maxBytes)
+		})
+	}
+}