Make ShredStorageType::RocksLevel public (#23272)

#### Summary of Changes
This PR adds two hidden arguments to the validator that allow users to use RocksDB's FIFO compaction for storing shreds.

        --shred-storage <SHRED_STORAGE>
            EXPERIMENTAL: Controls how RocksDB compacts shreds.  *WARNING*: You will lose your ledger data
            when you switch between options. Possible values are: 'level': stores shreds using RocksDB's default (level)
            compaction. 'fifo': stores shreds under RocksDB's FIFO compaction. This option is more efficient on
            disk-write-bytes of the ledger store. [default: level]  [possible values: level, fifo]

        --shred-storage-size <SHRED_STORAGE_SIZE_BYTES>
            The shred storage size in bytes. The suggested value is 50% of your ledger storage size in bytes. [default:
            268435456000]

local-cluster/src/validator_configs.rs

@@ -62,6 +62,7 @@ pub fn safe_clone_config(config: &ValidatorConfig) -> ValidatorConfig {
         accounts_shrink_ratio: config.accounts_shrink_ratio,
         accounts_db_config: config.accounts_db_config.clone(),
         wait_to_vote_slot: config.wait_to_vote_slot,
+        shred_storage_type: config.shred_storage_type.clone(),
     }
 }