Add item creation and "get all" endpoints.

src/main/sql/init_database.sql

@@ -0,0 +1,14 @@
+\c virtual_threads_db;
+
+CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
+
+CREATE TABLE IF NOT EXISTS catalog (
+    id UUID NOT NULL PRIMARY KEY,
+    name VARCHAR NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS item (
+    id UUID NOT NULL PRIMARY KEY,
+    name VARCHAR NOT NULL,
+    shared_date TIMESTAMP WITH TIME ZONE NULL
+);