Add a command or function - Remove and Sort Usings

## Is your feature request related to a problem? Please describe.

## Describe the solution you would like
- Add one item, "Remove and Sort Usings" in the right menu;
- Add some configs to set the sort and group rule
- A config flag to decide to add a new line when grouping Usings

## Applicable Scenarios
- Remove unused using statement
- Sort and group using statement
- Format code

## Describe alternatives you've considered
- Use Visual Studio to sort and group the using statement.

## Additional context
- Raw (Before updated):

- Updated: