Upgrade to v5 schema

Now uses:
* ipld direct_by_leaf StateDB for basic queries
* trie_by_cid StateDB for trie slice and proof queries

Also:
* vulcanize => cerc refactor
* Backend method to close dbs
* state tests are in multiple packages, to allow separate ginkgo suites
* removes gap-filler module
* integration tests and github workflows
* run stack-orchestrator for testnet
* fix various issues with tests, hardhat server, dockerfile
* fix cmd flags / env vars
* fix flaky tests and clean up code
* remove unused code, scripts
* remove outdated docs
* update version

pkg/graphql/schema.go

@@ -292,7 +292,7 @@ const schema string = `
         index: Int!
         src: String!
         dst: String!
-        blockByMhKey: IPFSBlock!
+        blockByCid: IPFSBlock!
     }
 
     type EthTransactionCidsConnection {
@@ -317,7 +317,7 @@ const schema string = `
         uncleRoot: String!
         bloom: String!
         ethTransactionCidsByHeaderId: EthTransactionCidsConnection!
-        blockByMhKey: IPFSBlock!
+        blockByCid: IPFSBlock!
     }
 
     type EthHeaderCidsConnection {