ioctl node reward command to support delegate name

[dustinxie]

What would you like to be added

ioctl node reward unclaimed [DELEGATE_ADDRESS] only support query by delegate's owner address. Make it also work by delegate's name

Why is this needed

make it convenient for delegate, and improve user experience

How important you think this is for IoTeX

• must have
• [] should have
• [] nice to have

Additional information

Let us know any background or context that would help us better understand the request (for example the particular use-case that prompted this request)