chore: add derpserver to wsproxy, add proxies to derpmap (#7311)

coderd/database/migrations/000142_proxy_derp.down.sql

@@ -0,0 +1,15 @@
+BEGIN;
+
+-- drop any rows that aren't primary replicas
+DELETE FROM replicas
+	WHERE "primary" = false;
+
+ALTER TABLE replicas
+	DROP COLUMN "primary";
+
+ALTER TABLE workspace_proxies
+	DROP CONSTRAINT workspace_proxies_region_id_unique,
+	DROP COLUMN region_id,
+	DROP COLUMN derp_enabled;
+
+COMMIT;

coderd/database/migrations/000142_proxy_derp.up.sql

@@ -0,0 +1,13 @@
+BEGIN;
+
+ALTER TABLE replicas
+	ADD COLUMN "primary" boolean NOT NULL DEFAULT true;
+
+ALTER TABLE workspace_proxies
+	-- Adding a serial to a table without a default value will be filled as you
+	-- would expect on versions of Postgres >= 9 AFAIK (which we require).
+	ADD COLUMN region_id serial NOT NULL,
+	ADD COLUMN derp_enabled boolean NOT NULL DEFAULT true,
+	ADD CONSTRAINT workspace_proxies_region_id_unique UNIQUE (region_id);
+
+COMMIT;