* let drop column can drop index which column only have single-value index.

* Fix typo

* Remove unused codes and fix delete range when drop column with single-value index

* Let drop columns can delete single value index related columns

* Refactor unit test

* Add index exists test on drop composite index

* Add invisible index test and more result check on drop column

* Fix typo and refactor indexInfoContains

* Update comments

* Remove unnecessary code

* Remove unused codes

* Fix typo

* Remove unused code and fix comments

* Refactor, remove useless codes
Co-authored-by: bb7133 <bb7133@gmail.com>
Co-authored-by: Arenatlx <ailinsilence4@gmail.com>
Co-authored-by: ti-srebot <66930949+ti-srebot@users.noreply.github.com>