`STRICT_TRANS_TABLES` mode should not allow empty strings for integers

MySQL errors out on the following but Dolt allows it (MySQL allows it when `STRICT_TRANS_TABLES` mode is turned off)
```
mysql> CREATE TABLE t6(t6c0 VARCHAR(500), t6c1 INT, PRIMARY KEY(t6c0));
Query OK, 0 rows affected (0.01 sec)

mysql> INSERT INTO t6(t6c0, t6c1) VALUES (true, '');
ERROR 1366 (HY000): Incorrect integer value: '' for column 't6c1' at row 1
```

Start by reproducing the CREATE TABLE and INSERT statements in the issue with STRICT_TRANS_TABLES enabled, then compare Dolt's result with MySQL's error. Trace the relevant integer conversion behavior and finish when inserting an empty string into the INT column is rejected with MySQL-compatible behavior.

Written by the indexing model from the issue text.