Add Kaitai definitions for primary and secondary files

Author: jasagredo

ouroboros-consensus-cardano/cddl/disk/immutable/primary.ksy

@@ -0,0 +1,12 @@
+meta:
+  id: primary_file
+  endian: be
+
+seq:
+  - id: current_version
+    type: u1
+    valid: 0x01
+
+  - id: secondary_offsets
+    type: u4
+    repeat: eos

ouroboros-consensus-cardano/cddl/disk/immutable/secondary.ksy

@@ -0,0 +1,29 @@
+meta:
+  id: secondary_file
+  endian: be
+
+types:
+  entry:
+    seq:
+      - id: block_offset
+        type: u8
+
+      - id: header_offset
+        type: u2
+
+      - id: header_size
+        type: u2
+
+      - id: crc
+        type: u4
+
+      - id: header_hash
+        size: 32
+
+      - id: block_or_ebb
+        type: u8
+
+seq:
+  - id: secondary_offsets
+    type: entry
+    repeat: eos