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* remove outdated docs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

test/compose-db.yml

@@ -0,0 +1,26 @@
+# Containers to run a DB instance for tests
+
+services:
+  migrations:
+    restart: on-failure
+    depends_on:
+      - ipld-eth-db
+    image: git.vdb.to/cerc-io/ipld-eth-db/ipld-eth-db:v5.0.2-alpha
+    environment:
+      DATABASE_USER: "vdbm"
+      DATABASE_NAME: "cerc_testing"
+      DATABASE_PASSWORD: "password"
+      DATABASE_HOSTNAME: "ipld-eth-db"
+      DATABASE_PORT: 5432
+
+  ipld-eth-db:
+    container_name: test-ipld-eth-db
+    image: timescale/timescaledb:latest-pg14
+    restart: always
+    command: ["postgres", "-c", "log_statement=all"]
+    environment:
+      POSTGRES_USER: "vdbm"
+      POSTGRES_DB: "cerc_testing"
+      POSTGRES_PASSWORD: "password"
+    ports:
+      - 127.0.0.1:8077:5432