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" />

consensus/state_processing/src/per_block_processing.rs

@@ -47,6 +47,7 @@ use crate::common::update_progressive_balances_cache::{
 use crate::epoch_cache::initialize_epoch_cache;
 #[cfg(feature = "arbitrary-fuzz")]
 use arbitrary::Arbitrary;
+use tracing::instrument;
 
 /// The strategy to be used when validating the block's signatures.
 #[cfg_attr(feature = "arbitrary-fuzz", derive(Arbitrary))]
@@ -97,6 +98,7 @@ pub enum VerifyBlockRoot {
 /// re-calculating the root when it is already known. Note `block_root` should be equal to the
 /// tree hash root of the block, NOT the signing root of the block. This function takes
 /// care of mixing in the domain.
+#[instrument(skip_all)]
 pub fn per_block_processing<E: EthSpec, Payload: AbstractExecPayload<E>>(
     state: &mut BeaconState<E>,
     signed_block: &SignedBeaconBlock<E, Payload>,