strictNullChecks was off for docs, which lets errors slip through and
leads to incorrect required/optional typing on Zod-inferred types. This
PR enables strictNullChecks and fixes all the existing violations.
* exclude dart, python, and swift from error codes menu
* Update the error code doc to be client lib agnostic
* run formatter
* Add a filter to filter out section items
* Update apps/docs/components/Navigation/NavigationMenu/NavigationMenuRefList.tsx
* docs: move error codes table in a separate component
* Add auth error codes section for kotlin