tests/e2e: replace PoS test epoch waits with epoch-sleeps

PoS hammered the node as fast as possible with epoch queries in its
tests to wait for a specified epoch. Instead, epoch-sleep repeatedly
until the target epoch has been reached.

This could be improved further by adding an --until parameter to
epoch-sleep.

tests/src/e2e/ledger_tests.rs

@@ -1993,7 +1993,7 @@ fn pos_bonds() -> Result<()> {
                 delegation_withdrawable_epoch
             );
         }
-        let epoch = get_epoch(&test, &validator_one_rpc)?;
+        let epoch = epoch_sleep(&test, &validator_one_rpc, 40)?;
         if epoch >= delegation_withdrawable_epoch {
             break;
         }
@@ -2186,7 +2186,7 @@ fn pos_rewards() -> Result<()> {
         if Instant::now().duration_since(start) > loop_timeout {
             panic!("Timed out waiting for epoch: {}", wait_epoch);
         }
-        let epoch = get_epoch(&test, &validator_zero_rpc)?;
+        let epoch = epoch_sleep(&test, &validator_zero_rpc, 40)?;
         if dbg!(epoch) >= wait_epoch {
             break;
         }
@@ -2268,7 +2268,7 @@ fn test_bond_queries() -> Result<()> {
         if Instant::now().duration_since(start) > loop_timeout {
             panic!("Timed out waiting for epoch: {}", 1);
         }
-        let epoch = get_epoch(&test, &validator_one_rpc)?;
+        let epoch = epoch_sleep(&test, &validator_one_rpc, 40)?;
         if epoch >= Epoch(4) {
             break;
         }
@@ -2325,7 +2325,7 @@ fn test_bond_queries() -> Result<()> {
         if Instant::now().duration_since(start) > loop_timeout {
             panic!("Timed out waiting for epoch: {}", 7);
         }
-        let epoch = get_epoch(&test, &validator_one_rpc)?;
+        let epoch = epoch_sleep(&test, &validator_one_rpc, 40)?;
         if epoch >= Epoch(7) {
             break;
         }
@@ -2565,7 +2565,7 @@ fn pos_init_validator() -> Result<()> {
         if Instant::now().duration_since(start) > loop_timeout {
             panic!("Timed out waiting for epoch: {}", earliest_update_epoch);
         }
-        let epoch = get_epoch(&test, &non_validator_rpc)?;
+        let epoch = epoch_sleep(&test, &non_validator_rpc, 40)?;
         if epoch >= earliest_update_epoch {
             break;
         }