Revert nextRowset changes

[david-puglielli]

Reverting changes because several users have run into errors under the changes made to the way empty and null results are handled, and because the changes caused problems with multi-query statements. The original approach generally produced error messages only upon fetching, and next_result or nextRowset should simply move the cursor.

This change is 

[coveralls]

Coverage increased (+0.08%) to 72.767% when pulling 633024c on david-puglielli:nextrowset-revert into 04f5034 on Microsoft:dev.

[yitam]

Please justify in this pull request why reverting to the previous way is necessary. Also, the tests can be further simplified / refactored to use much less code (too many repeated lines). It would also be easier to understand the test if you compare expected results / error messages within the test itself rather than relying on the expected output

[codecov-io]

Codecov Report

Merging #595 into dev will decrease coverage by 0.15%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##              dev     #595      +/-   ##
==========================================
- Coverage   74.47%   74.31%   -0.16%     
==========================================
  Files          50       50              
  Lines       14949    14900      -49     
==========================================
- Hits        11133    11073      -60     
- Misses       3816     3827      +11

Impacted Files	Coverage Δ
...rojects/php/x86/php-7.0.25-src/ext/sqlsrv/conn.cpp	79.75% <0%> (-3.12%)	⬇️
.../php/x86/php-7.0.25-src/ext/pdo_sqlsrv/pdo_dbh.cpp	90.27% <0%> (-2.02%)	⬇️
...cts/php/x86/php-7.0.25-src/ext/sqlsrv/php_sqlsrv.h	60.71% <0%> (-0.47%)	⬇️
...rojects/php/x86/php-7.0.25-src/ext/sqlsrv/util.cpp	81.77% <0%> (-0.27%)	⬇️
...rojects/php/x86/php-7.1.11-src/ext/sqlsrv/stmt.cpp	87.67% <0%> (-0.27%)	⬇️
...rojects/php/x86/php-7.0.25-src/ext/sqlsrv/init.cpp	88.67% <0%> (-0.21%)	⬇️
.../php/x86/php-7.1.11-src/ext/pdo_sqlsrv/pdo_dbh.cpp	92.08% <0%> (-0.21%)	⬇️
...rojects/php/x86/php-7.0.25-src/ext/sqlsrv/stmt.cpp	87.82% <0%> (-0.17%)	⬇️
...x86/php-7.1.11-src/ext/sqlsrv/shared/core_stmt.cpp	80.63% <0%> (-0.12%)	⬇️
...x86/php-7.0.25-src/ext/sqlsrv/shared/core_stmt.cpp	78.76% <0%> (-0.12%)	⬇️
... and 7 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 04f5034...0088d61. Read the comment docs.

[coveralls]

Coverage increased (+0.08%) to 72.767% when pulling b2e9621 on david-puglielli:nextrowset-revert into 04f5034 on Microsoft:dev.

[coveralls]

Coverage increased (+0.08%) to 72.767% when pulling 0088d61 on david-puglielli:nextrowset-revert into 04f5034 on Microsoft:dev.

[yitam]

#581