feat: Add user roles, but do not yet enforce them (#1200)

* chore: Rework roles to be expandable by name alone

coderd/database/migrations/000008_rbac_roles.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE ONLY users
+	DROP COLUMN IF EXISTS rbac_roles;

coderd/database/migrations/000008_rbac_roles.up.sql

@@ -0,0 +1,18 @@
+ALTER TABLE ONLY users
+	ADD COLUMN IF NOT EXISTS rbac_roles text[] DEFAULT '{}' NOT NULL;
+
+-- All users are site members. So give them the standard role.
+-- Also give them membership to the first org we retrieve. We should only have
+-- 1 organization at this point in the product.
+UPDATE
+    users
+SET
+    rbac_roles = ARRAY ['member', 'organization-member:' || (SELECT id FROM organizations LIMIT 1)];
+
+-- Give the first user created the admin role
+UPDATE
+	users
+SET
+	rbac_roles = rbac_roles || ARRAY ['admin']
+WHERE
+	id = (SELECT id FROM users ORDER BY created_at ASC LIMIT 1)