Companion for #7997 (#2345)

* Companion for #7997

https://github.com/paritytech/substrate/pull/7997

* rename slot_number to slot

* rename SlotNumber type in overseer docs

* "Update Substrate"

Co-authored-by: André Silva <andrerfosilva@gmail.com>
Co-authored-by: parity-processbot <>

polkadot/roadmap/implementers-guide/src/node/approval/approval-voting.md

@@ -71,7 +71,7 @@ struct CandidateEntry {
 struct BlockEntry {
     block_hash: Hash,
     session: SessionIndex,
-    slot: SlotNumber,
+    slot: Slot,
     // random bytes derived from the VRF submitted within the block by the block
     // author as a credential and used as input to approval assignment criteria.
     relay_vrf_story: [u8; 32],

polkadot/roadmap/implementers-guide/src/types/overseer-protocol.md

@@ -101,8 +101,8 @@ struct BlockApprovalMeta {
     /// The candidates included by the block. Note that these are not the same as the candidates that appear within the
     /// block body.
     candidates: Vec<CandidateHash>,
-    /// The consensus slot number of the block.
-    slot_number: SlotNumber,
+    /// The consensus slot of the block.
+    slot: Slot,
 }
 
 enum ApprovalDistributionMessage {