Persist light client bootstrap (#5915)

* persist light client updates

* update beacon chain to serve light client updates

* resolve todos

* cache best update

* extend cache parts

* is better light client update

* resolve merge conflict

* initial api changes

* add lc update db column

* fmt

* added tests

* add sim

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into persist-light-client-updates

* fix some weird issues with the simulator

* tests

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into persist-light-client-updates

* test changes

* merge conflict

* testing

* started work on ef tests and some code clean up

* update tests

* linting

* noop pre altair, were still failing on electra though

* allow for zeroed light client header

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into persist-light-client-updates

* merge unstable

* remove unwraps

* remove unwraps

* fetch bootstrap without always querying for state

* storing bootstrap parts in db

* mroe code cleanup

* test

* prune sync committee branches from dropped chains

* Update light_client_update.rs

* merge unstable

* move functionality to helper methods

* refactor is best update fn

* refactor is best update fn

* improve organization of light client server cache logic

* fork diget calc, and only spawn as many blcoks as we need for the lc update test

* resovle merge conflict

* add electra bootstrap logic, add logic to cache current sync committee

* add latest sync committe branch cache

* fetch lc update from the cache if it exists

* fmt

* Fix beacon_chain tests

* Add debug code to update ranking_order ef test

* Fix compare code

* merge conflicts

* merge conflict

* add better error messaging

* resolve merge conflicts

* remove lc update from basicsim

* rename sync comittte variable and fix persist condition

* refactor get_light_client_update logic

* add better comments, return helpful error messages over http and rpc

* pruning canonical non checkpoint slots

* fix test

* rerun test

* update pruning logic, add tests

* fix tests

* fix imports

* fmt

* refactor db code

* Refactor db method

* Refactor db method

* add additional comments

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into persist-light-client-bootstrap

* fix merge

* linting

* merge conflict

* prevent overflow

* enable lc server for http api tests

* fix tests

* remove prints

* remove warning

* revert change

beacon_node/store/src/lib.rs

@@ -241,6 +241,7 @@ pub enum StoreOp<'a, E: EthSpec> {
     DeleteDataColumns(Hash256, Vec<ColumnIndex>),
     DeleteState(Hash256, Option<Slot>),
     DeleteExecutionPayload(Hash256),
+    DeleteSyncCommitteeBranch(Hash256),
     KeyValueOp(KeyValueStoreOp),
 }
 
@@ -303,6 +304,12 @@ pub enum DBColumn {
     /// For persisting eagerly computed light client data
     #[strum(serialize = "lcu")]
     LightClientUpdate,
+    /// For helping persist eagerly computed light client bootstrap data
+    #[strum(serialize = "scb")]
+    SyncCommitteeBranch,
+    /// For helping persist eagerly computed light client bootstrap data
+    #[strum(serialize = "scm")]
+    SyncCommittee,
 }
 
 /// A block from the database, which might have an execution payload or not.
@@ -346,6 +353,8 @@ impl DBColumn {
             | Self::BeaconHistoricalRoots
             | Self::BeaconHistoricalSummaries
             | Self::BeaconRandaoMixes
+            | Self::SyncCommittee
+            | Self::SyncCommitteeBranch
             | Self::LightClientUpdate => 8,
             Self::BeaconDataColumn => DATA_COLUMN_DB_KEY_SIZE,
         }