Move SnapshotConfig into its own module (#18331)

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

runtime/src/snapshot_config.rs

@@ -0,0 +1,26 @@
+use crate::snapshot_utils::ArchiveFormat;
+use crate::snapshot_utils::SnapshotVersion;
+use solana_sdk::clock::Slot;
+use std::path::PathBuf;
+
+/// Snapshot configuration and runtime information
+#[derive(Clone, Debug)]
+pub struct SnapshotConfig {
+    /// Generate a new snapshot every this many slots
+    pub snapshot_interval_slots: Slot,
+
+    /// Where to store the latest packaged snapshot
+    pub snapshot_package_output_path: PathBuf,
+
+    /// Where to place the snapshots for recent slots
+    pub snapshot_path: PathBuf,
+
+    /// The archive format to use for snapshots
+    pub archive_format: ArchiveFormat,
+
+    /// Snapshot version to generate
+    pub snapshot_version: SnapshotVersion,
+
+    /// Maximum number of snapshots to retain
+    pub maximum_snapshots_to_retain: usize,
+}