Set up PostgreSQL database configuration and enhance application structure

- Added .env.example with database connection details and JWT configuration.
- Introduced docker-compose.yml for PostgreSQL service setup with health checks.
- Created drizzle.config.ts for database schema and migration management.
- Updated nest-cli.json to include Swagger plugin configuration for API documentation.
- Enhanced package.json with new database-related scripts and dependencies.
- Implemented initial database migrations for user and token management.
- Configured application bootstrap process to load environment variables and set up Swagger.
- Added shared application configuration in configure-app.ts for consistent setup.
- Included unit tests for application configuration and Swagger setup.

drizzle/migrations/0000_jazzy_tomorrow_man.sql

@@ -0,0 +1,27 @@
+CREATE TABLE "refresh_tokens" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"user_id" uuid NOT NULL,
+	"token_hash" text NOT NULL,
+	"access_jti" text NOT NULL,
+	"expires_at" bigint NOT NULL,
+	"revoked_at" bigint,
+	"replaced_by" uuid,
+	"created_at" bigint NOT NULL
+);
+--> statement-breakpoint
+CREATE TABLE "revoked_access_tokens" (
+	"jti" text PRIMARY KEY NOT NULL,
+	"expires_at" bigint NOT NULL
+);
+--> statement-breakpoint
+CREATE TABLE "users" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"username" text NOT NULL,
+	"password_hash" text NOT NULL,
+	"created_at" bigint NOT NULL,
+	"updated_at" bigint NOT NULL
+);
+--> statement-breakpoint
+ALTER TABLE "refresh_tokens" ADD CONSTRAINT "refresh_tokens_user_id_users_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."users"("id") ON DELETE cascade ON UPDATE no action;--> statement-breakpoint
+CREATE UNIQUE INDEX "refresh_tokens_token_hash_unique" ON "refresh_tokens" USING btree ("token_hash");--> statement-breakpoint
+CREATE UNIQUE INDEX "users_username_unique" ON "users" USING btree ("username");