Implement Overflow LRU Cache for Pending Blobs (#4203)

* All Necessary Objects Implement Encode/Decode

* Major Components for LRUOverflowCache Implemented

* Finish Database Code

* Add Maintenance Methods

* Added Maintenance Service

* Persist Blobs on Shutdown / Reload on Startup

* Address Clippy Complaints

* Add (emum_behaviour = "tag") to ssz_derive

* Convert Encode/Decode Implementations to "tag"

* Started Adding Tests

* Added a ton of tests

* 1 character fix

* Feature Guard Minimal Spec Tests

* Update beacon_node/beacon_chain/src/data_availability_checker.rs

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

* Address Sean's Comments

* Add iter_raw_keys method

* Remove TODOs

---------

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

beacon_node/client/src/builder.rs

@@ -2,6 +2,7 @@ use crate::address_change_broadcast::broadcast_address_changes_at_capella;
 use crate::config::{ClientGenesis, Config as ClientConfig};
 use crate::notifier::spawn_notifier;
 use crate::Client;
+use beacon_chain::data_availability_checker::start_availability_cache_maintenance_service;
 use beacon_chain::otb_verification_service::start_otb_verification_service;
 use beacon_chain::proposer_prep_service::start_proposer_prep_service;
 use beacon_chain::schema_change::migrate_schema;
@@ -828,6 +829,10 @@ where
 
             start_proposer_prep_service(runtime_context.executor.clone(), beacon_chain.clone());
             start_otb_verification_service(runtime_context.executor.clone(), beacon_chain.clone());
+            start_availability_cache_maintenance_service(
+                runtime_context.executor.clone(),
+                beacon_chain.clone(),
+            );
         }
 
         Ok(Client {