insertSpaces formatting option doesn't always work

Steps to reproduce. Run the following program using ts-node or similar.

import { format, applyEdits } from 'jsonc-parser';
const JSONString = `{"hello": \t"\tworld"}`;
const edit = format(JSONString, undefined, { insertSpaces: true});
const res = applyEdits(JSONString, edit);
console.log(res);

We would expect the following output

{
    "hello": "       world"
}

But we actually get

{
    "hello":    "       world"
}

Interestingly, if we remove the tab inside the quotes, the tab outside is removed as expected. This seems like an error since formatting should only care about tabs outside quotes.

Start by running the provided ts-node reproduction and tracing the format and applyEdits entry points. Add a regression test covering a tab inside a quoted value alongside an indentation tab, and verify that formatting removes only the tab outside the quotes.