Automatically create sort groups based on newlines in organize imports

[MQuy]

Closes #41494.

Based on @RyanCavanaugh's suggestion #41494 (comment)

when organizing imports in each block of newline-contiguous

import c from "C"; import d from "D"; import a from "A"; import b from "B";

turns into

import c from "C"; import a from "A"; import b from "B"; import d from "D";

[jakebailey]

This looks about right to me, but I think what I'd like to see are a few more tests to cover cases where there are comments, e.g., what is the behavior when we have something like:

// polyfill import "lib" // not polyfill import { b } from "lib2"

or say

import "lib" // xyz import c from "C"

Or similar (this isn't exhaustive). I know the original issue had some code snippets that feature comments.