Request: option to let `no-duplicates` force type & normal imports to be de-duplicated

#225 asked to allow both type & normal imports to be allowed together, e.g.

import {someFunction} from '../src/foo';
import type {someType} from '../src/foo';

This was requested because according to the author there was no way to merge these together at that point in time.

However, currently flow does support merging these imports together:

import { someFunction, type someType } from '../src/foo';

I think it would therefore be useful if no-duplicates could be configured to have the same behaviour as before #225, i.e. to require type & normal imports to be merged.