Rename file when renaming default export

Currently we can use the `rename symbol` command and that will rename the symbol and its usages (exports, imports, usages in other files, etc.). That's a great start, but I'd love to see this feature expanded to do the following: - Many times a file name will coincide with the symbol being refactored. The refactor option should be available when renaming the file, so everything can be done at once. - In addition to the refactor changing symbol references across all files, it'd be nice to have the ability to also update comments, strings, etc. that refer to that symbol. **Code Example:** _Shape.js_ ```javascript class Shape {} export default Shape; ``` _Circle.js - We reference Shape as an import, extends, inside a comment, and inside a string. They should all be refactored._ ```javascript import Shape from "./Shape"; // Shape subclass class Circle extends Shape { constructor() { super(); console.log('A circle is a Shape.'); } } export default Circle; ``` **WebStorm Examples** <img width="1440" alt="screen shot 2019-01-04 at 8 36 22 pm" src="https://user-images.githubusercontent.com/12591890/50719461-c1c07b00-1061-11e9-96f2-768c81458e24.png"> <img width="1440" alt="screen shot 2019-01-04 at 8 37 02 pm" src="https://user-images.githubusercontent.com/12591890/50719462-c1c07b00-1061-11e9-9f82-1a2af9ca3ba7.png">