Convert Blockstore Rewards cf to protobuf (#12860)

* Add Blockstore protobuf cf type

* Add Rewards message to proto and make generated pub

* Convert Rewards cf to ProtobufColumn

* Add bench

* Adjust tags

* Move solana proto definitions and conversion methods to new crate

storage-proto/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "solana-storage-proto"
+version = "1.5.0"
+description = "Solana Storage Protobuf Definitions"
+authors = ["Solana Maintainers <maintainers@solana.com>"]
+repository = "https://github.com/solana-labs/solana"
+license = "Apache-2.0"
+homepage = "https://solana.com/"
+edition = "2018"
+
+[dependencies]
+bincode = "1.2.1"
+prost = "0.6.1"
+serde = "1.0.112"
+serde_derive = "1.0.103"
+solana-sdk = { path = "../sdk", version = "1.5.0" }
+solana-transaction-status = { path = "../transaction-status", version = "1.5.0" }
+
+[lib]
+crate-type = ["lib"]
+name = "solana_storage_proto"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]