Move SnapshotConfig into its own module (#18331)

Also move ArchiveFormat to snapshot_utils, and do not
reexport SnapshotVersion.

core/src/snapshot_packager_service.rs

@@ -78,9 +78,8 @@ mod tests {
     use solana_runtime::{
         accounts_db::AccountStorageEntry,
         bank::BankSlotDelta,
-        bank_forks::ArchiveFormat,
         snapshot_package::AccountsPackage,
-        snapshot_utils::{self, SnapshotVersion, SNAPSHOT_STATUS_CACHE_FILE_NAME},
+        snapshot_utils::{self, ArchiveFormat, SnapshotVersion, SNAPSHOT_STATUS_CACHE_FILE_NAME},
     };
     use solana_sdk::hash::Hash;
     use std::{