Move BlockProcessingResult match out of block lookups (#9327)

- https://github.com/sigp/lighthouse/pull/9155 remove the trait abstraction for processing block / blobs / columns / payloads

As a result we would have to duplicate x3 the big match on `BlockProcessingResult` we currently have in block lookups mod.rs

This PR moves the match of `BlockProcessingResult` to `sync_methods` to reduce the diff of https://github.com/sigp/lighthouse/pull/9155. There are some subtle changes that deserve dedicated attention, and may be drowned in the bigger diff of https://github.com/sigp/lighthouse/pull/9155 otherwise:

| Unstable | This PR / #9115 |
| - | - |
| Some error conditions immediately `Drop` the lookup (no retries). For example for "internal" errors like the BeaconChainError | Retries ALL errors 4 times. I believe assuming some errors are internal is risky as dropping a lookup drops all its children potentially forcing the node to resync a lot of blocks because of an internal timeout


  


Co-Authored-By: dapplion <35266934+dapplion@users.noreply.github.com>

beacon_node/network/src/sync/mod.rs

@@ -15,4 +15,5 @@ mod range_sync;
 mod tests;
 
 pub use manager::{BatchProcessResult, SyncMessage};
+pub use network_context::{PeerGroup, SyncNetworkContext};
 pub use range_sync::ChainId;