Fix generation of entities with the same name in one file

[raveclassic]

components:
  schemas:
    echo:
      description: echo
      type: string
  messages:
    echo:
      payload:
        $ref: '#/components/schemas/echo'

This piece will result in

import { echo, echoIO } from '../../components/schemas/echo';

export type echo = echo;
export const echoIO = echoIO;

We need to find a way to avoid such conflicts. Possibly using named imports.