As a node driver engineer,
I want to prevent variable shadowing except where absolutely necessary,
So that future engineers understand that shadowing is intentional in the places it exists in our codebase.

Acceptance Criteria

• Install https://eslint.org/docs/rules/no-shadow into the following repos
  • the driver
  • libmongocrypt node bindings
  • bson
• Address any new lint failures as a result of this rule.  If shadowing is necessary, add a comment explaining why.
• Search the codebase for this Jira ticket and address any TODOs (at the time of writing this ticket, there are 3).