Add Capella & Deneb light client support (#4946)

* rebase and add comment

* conditional test

* test

* optimistic chould be working now

* finality should be working now

* try again

* try again

* clippy fix

* add lc bootstrap beacon api

* add lc optimistic/finality update to events

* fmt

* That error isn't occuring on my computer but I think this should fix it

* Merge branch 'unstable' into light_client_beacon_api_1

# Conflicts:
#	beacon_node/beacon_chain/src/events.rs
#	beacon_node/http_api/src/lib.rs
#	beacon_node/http_api/src/test_utils.rs
#	beacon_node/http_api/tests/main.rs
#	beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
#	beacon_node/lighthouse_network/src/rpc/methods.rs
#	beacon_node/lighthouse_network/src/service/api_types.rs
#	beacon_node/network/src/beacon_processor/worker/rpc_methods.rs
#	beacon_node/tests/test.rs
#	common/eth2/src/types.rs
#	lighthouse/src/main.rs

* Add missing test file

* Update light client types to comply with Altair light client spec.

* Fix test compilation

* Merge branch 'unstable' into light_client_beacon_api_1

* Support deserializing light client structures for the Bellatrix fork

* Move `get_light_client_bootstrap` logic to `BeaconChain`. `LightClientBootstrap` API to return `ForkVersionedResponse`.

* Misc fixes.
- log cleanup
- move http_api config mutation to `config::get_config` for consistency
- fix light client API responses

* Add light client bootstrap API test and fix existing ones.

* Merge branch 'unstable' into light_client_beacon_api_1

* Fix test for `light-client-server` http api config.

* Appease clippy

* Add Altair light client SSZ tests

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into light_client_beacon_api_1

* updates to light client header

* light client header from signed beacon block

* using options

* implement helper functions

* placeholder conversion from vec hash256 to exec branch

* add deneb

* using fixed vector

* remove unwraps

* by epoch

* compute merkle proof

* merkle proof

* update comments

* resolve merge conflicts

* linting

* Merge branch 'unstable' into light-client-ssz-tests

# Conflicts:
#	beacon_node/beacon_chain/src/beacon_chain.rs
#	consensus/types/src/light_client_bootstrap.rs
#	consensus/types/src/light_client_header.rs

* superstruct attempt

* superstruct changes

* lint

* altair

* update

* update

* changes to light_client_optimistic_ and finality

* merge unstable

* refactor

* resolved merge conflicts

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into capella_deneb_light_client_types

* block_to_light_client_header fork aware

* fmt

* comment fix

* comment fix

* include merge fork, update deserialize_by_fork, refactor

* fmt

* pass by ref to prevent clone

* rename merkle proof fn

* add FIXME

* LightClientHeader TestRandom

* fix comments

* fork version deserialize

* merge unstable

* move fn arguments, fork name calc

* use task executor

* remove unneeded fns

* remove dead code

* add manual ssz decoding/encoding and add ssz_tests_by_fork macro

* merge deneb types with tests

* merge ssz tests, revert code deletion, cleanup

* move chainspec

* update ssz tests

* fmt

* light client ssz tests

* change to superstruct

* changes from feedback

* linting

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into capella_deneb_light_client_types

* test fix

* cleanup

* Remove unused `derive`.

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into capella_deneb_light_client_types

* beta compiler fix

* merge

beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs

@@ -590,9 +590,18 @@ fn handle_rpc_response<T: EthSpec>(
         SupportedProtocol::MetaDataV1 => Ok(Some(RPCResponse::MetaData(MetaData::V1(
             MetaDataV1::from_ssz_bytes(decoded_buffer)?,
         )))),
-        SupportedProtocol::LightClientBootstrapV1 => Ok(Some(RPCResponse::LightClientBootstrap(
-            LightClientBootstrap::from_ssz_bytes(decoded_buffer)?,
-        ))),
+        SupportedProtocol::LightClientBootstrapV1 => match fork_name {
+            Some(fork_name) => Ok(Some(RPCResponse::LightClientBootstrap(Arc::new(
+                LightClientBootstrap::from_ssz_bytes(decoded_buffer, fork_name)?,
+            )))),
+            None => Err(RPCError::ErrorResponse(
+                RPCResponseErrorCode::InvalidRequest,
+                format!(
+                    "No context bytes provided for {:?} response",
+                    versioned_protocol
+                ),
+            )),
+        },
         // MetaData V2 responses have no context bytes, so behave similarly to V1 responses
         SupportedProtocol::MetaDataV2 => Ok(Some(RPCResponse::MetaData(MetaData::V2(
             MetaDataV2::from_ssz_bytes(decoded_buffer)?,