refactor: workspace autostop_schedule -> ttl (#1578)

Co-authored-by: G r e y <grey@coder.com>

coderd/database/dump.sql

@@ -314,7 +314,7 @@ CREATE TABLE workspaces (
     deleted boolean DEFAULT false NOT NULL,
     name character varying(64) NOT NULL,
     autostart_schedule text,
-    autostop_schedule text
+    ttl bigint
 );
 
 ALTER TABLE ONLY licenses ALTER COLUMN id SET DEFAULT nextval('public.licenses_id_seq'::regclass);
@@ -483,4 +483,3 @@ ALTER TABLE ONLY workspaces
 
 ALTER TABLE ONLY workspaces
     ADD CONSTRAINT workspaces_template_id_fkey FOREIGN KEY (template_id) REFERENCES templates(id) ON DELETE RESTRICT;
-