Make account shrink configurable #17544 (backport #17778) (#18013)

* Make account shrink configurable #17544 (#17778)

1. Added both options for measuring space usage using total accounts usage and for individual store shrink ratio using an enum. Validator CLI options: --accounts-shrink-optimize-total-space and --accounts-shrink-ratio
2. Added code for selecting candidates based on total usage in a separate function select_candidates_by_total_usage
3. Added unit tests for the new functions added
4. The default implementations is kept at 0.8 shrink ratio with --accounts-shrink-optimize-total-space set to true

Fixes #17544

(cherry picked from commit 269d995832)

# Conflicts:
#	core/tests/snapshots.rs
#	ledger/src/bank_forks_utils.rs
#	runtime/src/accounts_db.rs
#	runtime/src/snapshot_utils.rs

* fix some merge errors

Co-authored-by: Lijun Wang <83639177+lijunwangs@users.noreply.github.com>
Co-authored-by: Jeff Washington (jwash) <wash678@gmail.com>

accounts-bench/src/main.rs

@@ -6,6 +6,7 @@ use rayon::prelude::*;
 use solana_measure::measure::Measure;
 use solana_runtime::{
     accounts::{create_test_accounts, update_accounts_bench, Accounts},
+    accounts_db::AccountShrinkThreshold,
     accounts_index::AccountSecondaryIndexes,
     ancestors::Ancestors,
 };
@@ -64,6 +65,7 @@ fn main() {
         &ClusterType::Testnet,
         AccountSecondaryIndexes::default(),
         false,
+        AccountShrinkThreshold::default(),
     );
     println!("Creating {} accounts", num_accounts);
     let mut create_time = Measure::start("create accounts");