[governance] add delegation staking pool implementation (MystenLabs#4187

)

* [governance] add draft delegation staking pool implementation

* distribute pool tokens at epoch boundaries

* refactor staking pool code and add delegation switching

* update rust version of sui system state

* [staking] use vector for pending delegations

crates/sui-config/tests/snapshots/snapshot_tests__populated_genesis_snapshot_matches-5.snap

@@ -210,15 +210,19 @@ validators:
         next_epoch_delegation: 0
         next_epoch_gas_price: 1
       stake_amount: 1
-      delegation: 0
       pending_stake: 0
       pending_withdraw: 0
-      pending_delegation: 0
-      pending_delegation_withdraw: 0
-      delegator_count: 0
-      pending_delegator_count: 0
-      pending_delegator_withdraw_count: 0
       gas_price: 1
+      delegation_staking_pool:
+        validator_address: 375741c9373ae27bde5e6b5f5cc79f074cd84587
+        starting_epoch: 1
+        epoch_starting_sui_balance: 0
+        sui_balance: 0
+        rewards_pool:
+          value: 0
+        delegation_token_supply:
+          value: 0
+        pending_delegations: []
   pending_validators: []
   pending_removals: []
   next_epoch_validators:
@@ -428,7 +432,5 @@ parameters:
   min_validator_stake: 100000000000000
   max_validator_candidate_count: 100
   storage_gas_price: 1
-delegation_reward:
-  value: 0
 reference_gas_price: 0
 

crates/sui-cost/tests/snapshots/empirical_transaction_cost__good_snapshot.snap

@@ -4,12 +4,12 @@ expression: common_costs
 ---
 {
   "MergeCoin": {
-    "computation_cost": 466,
+    "computation_cost": 482,
     "storage_cost": 32,
     "storage_rebate": 0
   },
   "Publish": {
-    "computation_cost": 524,
+    "computation_cost": 541,
     "storage_cost": 83,
     "storage_rebate": 0
   },
@@ -29,7 +29,7 @@ expression: common_costs
     "storage_rebate": 15
   },
   "SplitCoin": {
-    "computation_cost": 577,
+    "computation_cost": 593,
     "storage_cost": 80,
     "storage_rebate": 0
   },

crates/sui-framework/sources/epoch_time_lock.move

@@ -12,7 +12,7 @@ module sui::epoch_time_lock {
 
     /// Holder of an epoch number that can only be discarded in the epoch or
     /// after the epoch has passed.
-    struct EpochTimeLock has store {
+    struct EpochTimeLock has store, copy {
         epoch: u64
     }