add option to no-undeclared-env to include additional objects

[juliusmarminge]

Goals

1. Allow users who declare their environment variables using e.g. t3-env (https://env.t3.gg) or other validator based approaches to use this rule and get proper linting

Non-goals

Background

Currently, the rule is hard-coded to only check explicit access of keys on import.meta.env and process.env. This will not work for people who validate their environment variables using a validator based approach like

import { z } from 'zod'

export const env = z.object({
  FOO: z.string().min(6)
})
  .parse(
    // Next.js stopped doing static analysis on server keys a while ago so this is valid.
    process.env,

    // behavior for other frameworks may vary and require an explicit destructuring here
    // which would trigger lint warnings
    // { FOO: process.env.FOO }
  )

Later usage of env.FOO will not trigger a lint warning

Proposal

Add configuration to specify additional object names to apply the lint rule on. For example, Drizzle has drizzleObjectName config option: https://orm.drizzle.team/docs/eslint-plugin