pdctl: shuffer region scheduler and shuffer leader scheduler can set key range

## Feature Request
When I add shuffer region scheduler key range , I can find any args about for key range.

code location:

https://github.com/tikv/pd/blob/71ec276339b6e51fd1fc5eee36b569b8f6eea40c/tools/pd-ctl/pdctl/command/scheduler.go#L212-L218

### Describe your feature request related problem

### Describe the feature you'd like
The two scheduler should support to set key range

### Describe alternatives you've considered

### Teachability, Documentation, Adoption, Migration Strategy