fix(oci8): Check for error after fetching data

[ptgr]

• bug fix
• BC break? no

When oci8 driver is used and there is an subquery error then an exception is not thrown.

Let see the example:

• php.ini has option oci8.default_prefetch=100
• SELECT (SELECT col FROM table WHERE ...) AS subcol FROM dual => subquery error ORA-01427: single-row subquery returns more than one row
• The ORA error occurs during fetching of rows > 100 (due to prefetch)

1. fetch function returns first 100 rows -> ok
2. Then it try to returns next 100 rows but there is a subquery error so it returns false
3. The function does not check oci_error so it does not thrown an exception
4. Result is that we have only 100 rows

It is primary query error but I think that function should be able to handle it.
The fix I tested on Oracle version 19.0.0.0.0