(VDB-298) Consume Pit contract storage diffs

- Continuously parse storage diffs CSV data to read Pit contract state
- Convert ilks in database to raw bytes32 value for use in generating
  storage keys dynamically
- Persist storage diffs with block number and hash for validation

db/migrations/00071_create_pit_contract_storage_tables.sql

@@ -0,0 +1,52 @@
+-- +goose Up
+CREATE TABLE maker.pit_drip (
+  id            SERIAL PRIMARY KEY,
+  block_number  BIGINT,
+  block_hash    TEXT,
+  drip          TEXT
+);
+
+CREATE TABLE maker.pit_ilk_spot (
+  id            SERIAL PRIMARY KEY,
+  block_number  BIGINT,
+  block_hash    TEXT,
+  ilk           TEXT,
+  spot          NUMERIC NOT NULL
+);
+
+CREATE TABLE maker.pit_ilk_line (
+  id            SERIAL PRIMARY KEY,
+  block_number  BIGINT,
+  block_hash    TEXT,
+  ilk           TEXT,
+  line          NUMERIC NOT NULL
+);
+
+CREATE TABLE maker.pit_line (
+  id            SERIAL PRIMARY KEY,
+  block_number  BIGINT,
+  block_hash    TEXT,
+  line          NUMERIC NOT NULL
+);
+
+CREATE TABLE maker.pit_live (
+  id            SERIAL PRIMARY KEY,
+  block_number  BIGINT,
+  block_hash    TEXT,
+  live          NUMERIC NOT NULL
+);
+
+CREATE TABLE maker.pit_vat (
+  id            SERIAL PRIMARY KEY,
+  block_number  BIGINT,
+  block_hash    TEXT,
+  vat           TEXT
+);
+
+-- +goose Down
+DROP TABLE maker.pit_drip;
+DROP TABLE maker.pit_ilk_spot;
+DROP TABLE maker.pit_ilk_line;
+DROP TABLE maker.pit_line;
+DROP TABLE maker.pit_live;
+DROP TABLE maker.pit_vat;