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/network/src/message_handler.rs

@@ -43,7 +43,7 @@ pub enum HandlerMessage {
     PubsubMessage(String, PeerId, PubsubMessage),
 }
 
-impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
+impl<T: BeaconChainTypes> MessageHandler<T> {
     /// Initializes and runs the MessageHandler.
     pub fn spawn(
         beacon_chain: Arc<BeaconChain<T>>,

beacon_node/network/src/service.rs

@@ -24,7 +24,7 @@ pub struct Service<T: BeaconChainTypes> {
     _phantom: PhantomData<T>,
 }
 
-impl<T: BeaconChainTypes + 'static> Service<T> {
+impl<T: BeaconChainTypes> Service<T> {
     pub fn new(
         beacon_chain: Arc<BeaconChain<T>>,
         config: &NetworkConfig,