feat(log_store): introduce the CollectionTask (#4530)

* feat: introduce the `CollectionTask`

* feat: add config of index collector

* chore: remove unused code

* feat: truncate indexes

* chore: apply suggestions from CR

* chore: update config examples

* refactor: retrieve latest offset while dumping indexes

* chore: print warn

src/mito2/src/wal.rs

@@ -89,7 +89,7 @@ impl<S: LogStore> Wal<S> {
         move |region_id, last_entry_id, provider| -> BoxFuture<'_, Result<()>> {
             Box::pin(async move {
                 store
-                    .obsolete(provider, last_entry_id)
+                    .obsolete(provider, region_id, last_entry_id)
                     .await
                     .map_err(BoxedError::new)
                     .context(DeleteWalSnafu { region_id })
@@ -142,7 +142,7 @@ impl<S: LogStore> Wal<S> {
         provider: &Provider,
     ) -> Result<()> {
         self.store
-            .obsolete(provider, last_id)
+            .obsolete(provider, region_id, last_id)
             .await
             .map_err(BoxedError::new)
             .context(DeleteWalSnafu { region_id })

src/mito2/src/wal/raw_entry_reader.rs

@@ -168,6 +168,7 @@ mod tests {
         async fn obsolete(
             &self,
             _provider: &Provider,
+            _region_id: RegionId,
             _entry_id: EntryId,
         ) -> Result<(), Self::Error> {
             unreachable!()