Remove tuples from JSON RPC responses (#7806)

* Remove RpcConfirmedBlock tuple

* Remove getRecentBlockhash tuple

* Remove getProgramAccounts tuple

* Remove tuple from get_signature_confirmation_status

* Collect Rpc response types

* Camel-case epoch schedule for rpc response

* Remove getBlockCommitment tuple

* Remove getStorageTurn tuple

* Update json-rpc docs

sdk/src/epoch_schedule.rs

@@ -13,6 +13,7 @@ pub const MINIMUM_SLOTS_PER_EPOCH: u64 = 32;
 
 #[repr(C)]
 #[derive(Debug, Clone, Copy, PartialEq, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
 pub struct EpochSchedule {
     /// The maximum number of slots in each epoch.
     pub slots_per_epoch: u64,