[WIP] *: sql based TTL prototype

[otan]

Refs: #20239

demo@127.0.0.1:26257/defaultdb> create table t (pk int primary key, s string) ttl '30 seconds';
CREATE TABLE


Time: 5ms total (execution 5ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> insert into t (pk, s, crdb_internal_ttl_expiration) values (1, 'a', now()), (2, 'b', now() + '2 minutes'), (3, 'c', default);
INSERT 3


Time: 5ms total (execution 5ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> select * from t;
  pk | s
-----+----
   1 | a
   2 | b
   3 | c
(3 rows)


Time: 1ms total (execution 1ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> show schedules; select now(); show jobs;
          id         |        label         | schedule_status |           next_run           |  state  | recurrence | jobsrunning | owner |            created            |                           command
---------------------+----------------------+-----------------+------------------------------+---------+------------+-------------+-------+-------------------------------+---------------------------------------------------------------
  693394338706554881 | sql-stats-compaction | ACTIVE          | 2021-09-15 04:00:00+00       | pending | @hourly    |           0 | node  | 2021-09-15 03:45:59.021481+00 | {}
  693394391318134785 | TTL 52               | ACTIVE          | 2021-09-15 03:46:25.08418+00 | NULL    | * * * * *  |           0 | demo  | 2021-09-15 03:46:15.082784+00 | {"tableId": 52, "ttlColumn": "crdb_internal_ttl_expiration"}
(2 rows)

Note: timings for multiple statements on a single line are not supported. See https://go.crdb.dev/issue-v/48180/v21.2.

               now
---------------------------------
  2021-09-15 03:46:37.682025+00
(1 row)

demo@127.0.0.1:26257/defaultdb> select now(); select *, crdb_internal_ttl_expiration from t;
               now
---------------------------------
  2021-09-15 03:48:17.298784+00
(1 row)


demo@127.0.0.1:26257/defaultdb> select now(); select *, crdb_internal_ttl_expiration from t;
               now
---------------------------------
  2021-09-15 03:48:27.322659+00
(1 row)

Note: timings for multiple statements on a single line are not supported. See https://go.crdb.dev/issue-v/48180/v21.2.

  pk | s | crdb_internal_ttl_expiration
-----+---+-------------------------------
   1 | a | 2021-09-15 03:48:00.99088+00
   2 | b | 2021-09-15 03:50:00.99088+00
   3 | c | 2021-09-15 03:48:30.99088+00
(3 rows)

Note: timings for multiple statements on a single line are not supported. See https://go.crdb.dev/issue-v/48180/v21.2.

demo@127.0.0.1:26257/defaultdb> select now(); select *, crdb_internal_ttl_expiration from t;
               now
---------------------------------
  2021-09-15 03:49:01.705966+00
(1 row)

Note: timings for multiple statements on a single line are not supported. See https://go.crdb.dev/issue-v/48180/v21.2.

  pk | s | crdb_internal_ttl_expiration
-----+---+-------------------------------
   2 | b | 2021-09-15 03:50:00.99088+00
   3 | c | 2021-09-15 03:48:30.99088+00
(2 rows)

Note: timings for multiple statements on a single line are not supported. See https://go.crdb.dev/issue-v/48180/v21.2.

[cockroach-teamcity]

This change is