sql: implement hidden column element

TODO:

Epic: CRDB-31283
Fixes: #139605

Release note (sql change): The `ALTER TABLE t ALTER COLUMN c SET [NOT]
VISIBLE` statements now use the declarative schema changer.

Author: bghal

pkg/ccl/logictestccl/tests/3node-tenant/generated_test.go

@@ -123,6 +123,12 @@ func executeSupportedDDLs(
 		`ALTER TABLE testdb.testsc.t2 RENAME COLUMN k_renamed TO k`,
 	}
 
+	// DDLs supported in V26_1.
+	v261DDLs := []string{
+		`ALTER TABLE testdb.testsc.t2 ALTER COLUMN j SET NOT VISIBLE`,
+		`ALTER TABLE testdb.testsc.t2 ALTER COLUMN j SET VISIBLE`,
+	}
+
 	// Used to clean up our CREATE-d elements after we are done with them.
 	cleanup := []string{
 		`DROP INDEX testdb.testsc.t@idx`,
@@ -155,6 +161,13 @@ func executeSupportedDDLs(
 			}
 		}
 	}
+	if clusterVersion.AtLeast(clusterversion.V26_1.Version()) {
+		for _, ddl := range v261DDLs {
+			if err := helper.ExecWithGateway(r, nodes, ddl); err != nil {
+				return err
+			}
+		}
+	}
 
 	for _, ddl := range cleanup {
 		if err := helper.ExecWithGateway(r, nodes, ddl); err != nil {

pkg/ccl/logictestccl/tests/local-read-committed/generated_test.go

@@ -0,0 +1,17 @@
+statement ok
+CREATE TABLE t (c1 INT8);
+CREATE TABLE u (c1 INT8);
+
+query I colnames
+SELECT * FROM t
+----
+c1
+
+statement ok
+DROP TABLE t
+
+# FIXME: Why does the drop break this
+query ITTTT colnames
+SELECT * FROM u
+----
+c1  crdb_internal_mvcc_timestamp  tableoid  crdb_internal_origin_id  crdb_internal_origin_timestamp