Implement freezer database (#508)

* Implement freezer database for state vectors

* Improve BeaconState safe accessors

And fix a bug in the compact committees accessor.

* Banish dodgy type bounds back to gRPC

* Clean up

* Switch to exclusive end points in chunked vec

* Cleaning up and start of tests

* Randao fix, more tests

* Fix unsightly hack

* Resolve test FIXMEs

* Config file support

* More clean-ups, migrator beginnings

* Finish migrator, integrate into BeaconChain

* Fixups

* Fix store tests

* Fix BeaconChain tests

* Fix LMD GHOST tests

* Address review comments, delete 'static bounds

* Cargo format

* Address review comments

* Fix LMD ghost tests

* Update to spec v0.9.0

* Update to v0.9.1

* Bump spec tags for v0.9.1

* Formatting, fix CI failures

* Resolve accidental KeyPair merge conflict

* Document new BeaconState functions

* Fix incorrect cache drops in `advance_caches`

* Update fork choice for v0.9.1

* Clean up some FIXMEs

* Fix a few docs/logs

* Update for new builder paradigm, spec changes

* Freezer DB integration into BeaconNode

* Cleaning up

* This works, clean it up

* Cleanups

* Fix and improve store tests

* Refine store test

* Delete unused beacon_chain_builder.rs

* Fix CLI

* Store state at split slot in hot database

* Make fork choice lookup fast again

* Store freezer DB split slot in the database

* Handle potential div by 0 in chunked_vector

* Exclude committee caches from freezer DB

* Remove FIXME about long-running test

beacon_node/beacon_chain/src/eth1_chain.rs

@@ -293,7 +293,7 @@ fn eth1_block_hash_at_start_of_voting_period<T: EthSpec, S: Store>(
             .map_err(|e| Error::UnableToGetPreviousStateRoot(e))?;
 
         store
-            .get::<BeaconState<T>>(&prev_state_root)
+            .get_state::<T>(&prev_state_root, Some(slot))
             .map_err(|e| Error::StoreError(e))?
             .map(|state| state.eth1_data.block_hash)
             .ok_or_else(|| Error::PreviousStateNotInDB)
@@ -676,7 +676,7 @@ mod test {
             );
 
             store
-                .put(
+                .put_state(
                     &state
                         .get_state_root(prev_state.slot)
                         .expect("should find state root"),
@@ -738,7 +738,7 @@ mod test {
             );
 
             store
-                .put(
+                .put_state(
                     &state
                         .get_state_root(Slot::new(0))
                         .expect("should find state root"),