feat!(NODE-4701): remove default export and add named namespace export

[nbbeeken]

Description

What is changing?

Removes deprecated default export, adds a namespace export.

// typescript and es module users:
import * as BSON from 'bson'; // either
import { BSON, ObjectId } from 'bson'; // or

// nodejs commonjs users:
const BSON = require('bson');

The following is no longer supported:

import BSON from 'bson';

What is the motivation for this change?

The default had to be maintained explicitly, did not have access to the type definitions nor constants so it wasn't an equivalent import. default export has a lot of behavioral corner cases that we want to avoid.

Double check the following

• Ran npm run lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: <type>(NODE-xxxx)<!>: <description>
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[durran]

Evergreen failures: https://spruce.mongodb.com/task/node_bson_lint_run_checks_patch_35a92341c0860fb41cbd5761250c565154ce1353_63924527850e612fdca4e4fa_22_12_08_20_12_24/logs?execution=0

Update, disregard. I fixed them.