move `Transaction`, `ExecutionAddress` and `BloomLogs` to `base`

Preparation for EIP-7495 SSZ `StableContainer` which can only contain
immutable types in their fields.

beacon_chain/spec/datatypes/base.nim

@@ -373,6 +373,15 @@ type
     sync_committee_bits*: BitArray[SYNC_COMMITTEE_SIZE]
     sync_committee_signature*: TrustedSig
 
+  # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.2/specs/bellatrix/beacon-chain.md#custom-types
+  Transaction* = List[byte, Limit MAX_BYTES_PER_TRANSACTION]
+
+  ExecutionAddress* = object
+    data*: array[20, byte]  # TODO there's a network_metadata type, but the import hierarchy's inconvenient
+
+  BloomLogs* = object
+    data*: array[BYTES_PER_LOGS_BLOOM, byte]
+
   # https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.6/specs/phase0/beacon-chain.md#beaconblockheader
   BeaconBlockHeader* = object
     slot*: Slot
@@ -837,6 +846,30 @@ func hasSupermajoritySyncParticipation*(
 func hasSupermajoritySyncParticipation*(v: SomeSyncAggregate): bool =
   hasSupermajoritySyncParticipation(v.num_active_participants.uint64)
 
+func fromHex*(
+    T: typedesc[BloomLogs], s: string): T {.raises: [ValueError].} =
+  hexToByteArray(s, result.data)
+
+func fromHex*(
+    T: typedesc[ExecutionAddress], s: string): T {.raises: [ValueError].} =
+  hexToByteArray(s, result.data)
+
+proc writeValue*(
+    writer: var JsonWriter, value: ExecutionAddress) {.raises: [IOError].} =
+  writer.writeValue to0xHex(value.data)
+
+proc readValue*(
+    reader: var JsonReader,
+    value: var ExecutionAddress) {.raises: [IOError, SerializationError].} =
+  try:
+    hexToByteArray(reader.readValue(string), value.data)
+  except ValueError:
+    reader.raiseUnexpectedValue(
+      "ExecutionAddress value should be a valid hex string")
+
+func `$`*(v: ExecutionAddress): string =
+  v.data.toHex()
+
 chronicles.formatIt AttestationData: it.shortLog
 chronicles.formatIt Checkpoint: it.shortLog
 

beacon_chain/spec/datatypes/bellatrix.nim

@@ -35,15 +35,6 @@ const
   NEWPAYLOAD_TIMEOUT* = 8.seconds
 
 type
-  # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.2/specs/bellatrix/beacon-chain.md#custom-types
-  Transaction* = List[byte, Limit MAX_BYTES_PER_TRANSACTION]
-
-  ExecutionAddress* = object
-    data*: array[20, byte]  # TODO there's a network_metadata type, but the import hierarchy's inconvenient
-
-  BloomLogs* = object
-    data*: array[BYTES_PER_LOGS_BLOOM, byte]
-
   # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.2/specs/bellatrix/beacon-chain.md#executionpayload
   ExecutionPayload* = object
     # Execution block header fields
@@ -361,29 +352,6 @@ type
 func initHashedBeaconState*(s: BeaconState): HashedBeaconState =
   HashedBeaconState(data: s)
 
-func fromHex*(T: typedesc[BloomLogs], s: string): T {.
-     raises: [ValueError].} =
-  hexToByteArray(s, result.data)
-
-func fromHex*(T: typedesc[ExecutionAddress], s: string): T {.
-     raises: [ValueError].} =
-  hexToByteArray(s, result.data)
-
-proc writeValue*(
-    writer: var JsonWriter, value: ExecutionAddress) {.raises: [IOError].} =
-  writer.writeValue to0xHex(value.data)
-
-proc readValue*(reader: var JsonReader, value: var ExecutionAddress) {.
-     raises: [IOError, SerializationError].} =
-  try:
-    hexToByteArray(reader.readValue(string), value.data)
-  except ValueError:
-    raiseUnexpectedValue(reader,
-                         "ExecutionAddress value should be a valid hex string")
-
-func `$`*(v: ExecutionAddress): string =
-  v.data.toHex()
-
 func shortLog*(v: SomeBeaconBlock): auto =
   (
     slot: shortLog(v.slot),