feat(query-parser): allow falsy indentation, default to 2 space in toJSString, deprecate stringify

[Anemy]

As part of https://jira.mongodb.org/browse/COMPASS-6980 we need to make Compass not use stringify for query parsing so that we can retain multi-spaces in values. We also want to have more flexibility over how we indent those places. This pr adds that flexibility and a deprecated notice on stringify so hopefully we can avoid using it in future.

To see a quick example of the bug stringify usage causes in Compass, run a query with the following:

{
 name: 'te    st'
}

And then click on it in query history and observe the multiple spaces in te st are replaced by one space.