* 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>