Poh subsystem cleanup, genesis plumbing, enable real PoH on edge testnet (#4292)

* Remove unused PohServiceConfig::Step

* Clarify variable name

* Poh::hash() now takes an iteration counter

* man -> max

* Inline functions with single call site

* Move PohServiceConfig into GenesisBlock

* Add plumbing to enable real PoH on testnets

* Batch hashes to improve PoH hash rate

* Ensure a constant hashes_per_tick

* Remove PohEntry mixin field

* Poh/PohEntry no longer maintains tick_height

* Ensure a constant hashes_per_tick

* ci/localnet-sanity.sh: Use real PoH

* Rework Poh/PohService to keep PohRecorder unlocked as much as possible while hashing

sdk/src/genesis_block.rs

@@ -3,6 +3,7 @@
 use crate::account::Account;
 use crate::fee_calculator::FeeCalculator;
 use crate::hash::{hash, Hash};
+use crate::poh_config::PohConfig;
 use crate::pubkey::Pubkey;
 use crate::signature::{Keypair, KeypairUtil};
 use crate::system_program;
@@ -21,6 +22,7 @@ pub struct GenesisBlock {
     pub slots_per_epoch: u64,
     pub stakers_slot_offset: u64,
     pub ticks_per_slot: u64,
+    pub poh_config: PohConfig,
 }
 
 // useful for basic tests
@@ -54,6 +56,7 @@ impl GenesisBlock {
             slots_per_epoch: DEFAULT_SLOTS_PER_EPOCH,
             stakers_slot_offset: DEFAULT_SLOTS_PER_EPOCH,
             ticks_per_slot: DEFAULT_TICKS_PER_SLOT,
+            poh_config: PohConfig::default(),
         }
     }