Name snapshots consistently (#19346)

#### Problem

Snapshot names are overloaded, and there are multiple terms that mean the same thing. This is confusing. Here's a list of ones in the codebase that I've found:

```
- snapshot_dir
- snapshots_dir
- snapshot_path
- snapshot_output_dir
- snapshot_package_output_path
- snapshot_archives_dir
```

#### Summary of Changes

For all the ones that are about the directory where snapshot archives are stored, ensure they are `snapshot_archives_dir`. For the ones about the (bank) snapshots directory, set to `bank_snapshots_dir`.


Co-authored-by: Michael Vines <mvines@gmail.com>

core/src/accounts_hash_verifier.rs

@@ -293,8 +293,8 @@ mod tests {
         let snapshot_config = SnapshotConfig {
             full_snapshot_archive_interval_slots,
             incremental_snapshot_archive_interval_slots: Slot::MAX,
-            snapshot_package_output_path: PathBuf::default(),
-            snapshot_path: PathBuf::default(),
+            snapshot_archives_dir: PathBuf::default(),
+            bank_snapshots_dir: PathBuf::default(),
             archive_format: ArchiveFormat::Tar,
             snapshot_version: SnapshotVersion::default(),
             maximum_snapshots_to_retain: usize::MAX,

core/src/snapshot_packager_service.rs

@@ -121,8 +121,8 @@ mod tests {
     fn create_and_verify_snapshot(temp_dir: &Path) {
         let accounts_dir = temp_dir.join("accounts");
         let snapshots_dir = temp_dir.join("snapshots");
-        let snapshot_package_output_path = temp_dir.join("snapshots_output");
-        fs::create_dir_all(&snapshot_package_output_path).unwrap();
+        let snapshot_archives_dir = temp_dir.join("snapshots_output");
+        fs::create_dir_all(&snapshot_archives_dir).unwrap();
 
         fs::create_dir_all(&accounts_dir).unwrap();
         // Create some storage entries
@@ -161,7 +161,7 @@ mod tests {
 
         // Create a packageable snapshot
         let output_tar_path = snapshot_utils::build_full_snapshot_archive_path(
-            snapshot_package_output_path,
+            snapshot_archives_dir,
             42,
             &Hash::default(),
             ArchiveFormat::TarBzip2,

core/src/test_validator.rs

@@ -523,8 +523,8 @@ impl TestValidator {
             snapshot_config: Some(SnapshotConfig {
                 full_snapshot_archive_interval_slots: 100,
                 incremental_snapshot_archive_interval_slots: Slot::MAX,
-                snapshot_path: ledger_path.join("snapshot"),
-                snapshot_package_output_path: ledger_path.to_path_buf(),
+                bank_snapshots_dir: ledger_path.join("snapshot"),
+                snapshot_archives_dir: ledger_path.to_path_buf(),
                 archive_format: ArchiveFormat::Tar,
                 snapshot_version: SnapshotVersion::default(),
                 maximum_snapshots_to_retain: DEFAULT_MAX_FULL_SNAPSHOT_ARCHIVES_TO_RETAIN,

core/src/validator.rs

@@ -1210,7 +1210,7 @@ fn new_banks_from_ledger(
             ledger_path,
             &bank_forks.root_bank(),
             None,
-            &snapshot_config.snapshot_package_output_path,
+            &snapshot_config.snapshot_archives_dir,
             snapshot_config.archive_format,
             Some(bank_forks.root_bank().get_thread_pool()),
             snapshot_config.maximum_snapshots_to_retain,