The AUTOCOMMIT OFF option is ignored in the Editor (4239948)

There is an issue with the AutoCommit option in the Editor not working when it is set from On to Off, and it seems that the AutoCommit option is not realising it's been turned off.

Steps to replicate:
- Open a new editor and paste in these commands (but don't run them)

select count (*) from SALES;

insert into sales values('324');

rollback;

select count (*) from SALES;


The test is just to go through the statements one by one to make sure they work as expected

Once the statements are pasted in the Editor:

1. Start new editor with AUTOCOMMIT OFF
2. Perform test => rollback performs as expected
3. Then in the same editor, choose AUTOCOMMIT ON
4. Perform test => results as expected, rollback has no effect because of the option: AUTOCOMMIT ON
5. Again in the same editor, choose AUTOCOMMIT OFF
6. Perform test => rollback has no effect, it looks like the insert statement autocommited, so no rollback is possible