chore: Rename 'admin' to 'owner' (#3498)

Co-authored-by: Colin Adler <colin1adler@gmail.com>

coderd/database/migrations/000034_remove_admin_role.down.sql

@@ -0,0 +1,22 @@
+UPDATE
+	users
+SET
+    -- Replace 'template-admin' and 'user-admin' role with 'admin'
+    rbac_roles = array_append(
+            array_remove(
+                array_remove(rbac_roles, 'template-admin'),
+                    'user-admin'
+                ), 'admin')
+WHERE
+    -- Only on existing admins. If they have either role, make them an admin
+    ARRAY ['template-admin', 'user-admin'] && rbac_roles;
+
+
+UPDATE
+    users
+SET
+    -- Replace 'owner' with 'admin'
+    rbac_roles = array_replace(rbac_roles, 'owner', 'admin')
+WHERE
+    -- Only on the owner
+    'owner' = ANY(rbac_roles);