Instrument tracing spans for block processing and import (#7816)

#7815

- removes all existing spans, so some span fields that appear in logs like `service_name` may be lost.
- instruments a few key code paths in the beacon node, starting from **root spans** named below:

* Gossip block and blobs
* `process_gossip_data_column_sidecar`
* `process_gossip_blob`
* `process_gossip_block`
* Rpc block and blobs
* `process_rpc_block`
* `process_rpc_blobs`
* `process_rpc_custody_columns`
* Rpc blocks (range and backfill)
* `process_chain_segment`
* `PendingComponents` lifecycle
* `pending_components`

To test locally:
* Run Grafana and Tempo with https://github.com/sigp/lighthouse-metrics/pull/57
* Run Lighthouse BN with `--telemetry-collector-url http://localhost:4317`

Some captured traces can be found here: https://hackmd.io/@jimmygchen/r1sLOxPPeg

Removing the old spans seem to have reduced the memory usage quite a lot - i think we were using them on long running tasks and too excessively:
<img width="910" height="495" alt="image" src="https://github.com/user-attachments/assets/5208bbe4-53b2-4ead-bc71-0b782c788669" />

beacon_node/beacon_chain/src/historical_blocks.rs

@@ -11,7 +11,7 @@ use std::time::Duration;
 use store::metadata::DataColumnInfo;
 use store::{AnchorInfo, BlobInfo, DBColumn, Error as StoreError, KeyValueStore, KeyValueStoreOp};
 use strum::IntoStaticStr;
-use tracing::debug;
+use tracing::{debug, instrument};
 use types::{FixedBytesExtended, Hash256, Slot};
 
 /// Use a longer timeout on the pubkey cache.
@@ -63,6 +63,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
     /// would violate consistency then an `AnchorInfoConcurrentMutation` error will be returned.
     ///
     /// Return the number of blocks successfully imported.
+    #[instrument(skip_all)]
     pub fn import_historical_block_batch(
         &self,
         mut blocks: Vec<AvailableBlock<T::EthSpec>>,