[CALCITE-6781] The isUpdateCapable method of calcite.avatica will incorrectly traverse the returned result value

[caicancai]

https://issues.apache.org/jira/browse/CALCITE-6781

Recently I am adapting the delete statement of es, but when I support delete * from where condition and similar statements, an error will be reported in the isUpdateCapable method, as follows
java.util.NoSuchElementException: Expecting cursor position to be Position.OK, actual is Position.AFTER_END

The reason is that the openResultSet.next() of the delete statement is false. In the current isUpdateCapable method, whether openResultSet.next() is true or false, it will perform subsequent operations.
But when openResultSet.next() is false,

statement.openResultSet.getObject(ROWCOUNT_COLUMN_NAME)
will throw the exception I encountered above

So when openResultSet.next() is false, it should return null directly.

I am not very familiar with the avatica module, and I am not sure where to add the test

I also have a second solution signature.statementType.canUpdate() returns false which can also solve this problem

[zabetak]

As I mentioned in the JIRA, without a test case or a clear problem statement/description it will not be easy to merge a fix.