sql: require any privilege on table-based SHOW commands

[maddyblue]

Fixes #8038

---

This change is

[tamird]

needs tests.

[maddyblue]

Added tests. Changed permissions to be any permission, similar to MySQL.

---

Review status: 0 of 4 files reviewed at latest revision, all discussions resolved, some commit checks pending.

---

Comments from Reviewable

[tamird]

---

Reviewed 4 of 4 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved, some commit checks pending.

---

Comments from Reviewable

[tamird]

Update the commit message and PR description plz

---

Review status: all files reviewed at latest revision, all discussions resolved, some commit checks pending.

---

Comments from Reviewable

[jseldess]

@mjibson, just starting to update the docs, but I'm confused about the results I'm getting for show columns. As a user who has no privileges on a certain table, users, I'm able to get a response. This PR is supposed to prevent that, right?

$ cockroach sql --user=jseldess
# Welcome to the cockroach SQL interface.
# All statements must be terminated by a semicolon.
# To exit: CTRL + D.

jseldess@:26257> show grants on test.users;
+-------+------+------------+
| Table | User | Privileges |
+-------+------+------------+
| users | root | ALL        |
+-------+------+------------+
(1 row)
jseldess@:26257> show columns from test.users;
+--------+-----------+-------+---------+
| Field  |   Type    | Null  | Default |
+--------+-----------+-------+---------+
| id     | INT       | false | NULL    |
| joined | TIMESTAMP | true  | NULL    |
| name   | STRING    | true  | NULL    |
| data   | BYTES     | true  | NULL    |
+--------+-----------+-------+---------+
(4 rows)

[maddyblue]

Yeah that's odd. Could you make an issue about this and assign it to me?

[jseldess]

Done, @mjibson: #8524

[jseldess]

Docs updated with cockroachdb/docs#558