tech debt: Deprecate Faker in stream maps context and recommend seed_instance

[edgarrmondragon]

Maybe I'm missing something, but could this not have been achieved already using seed_instance?

stream_maps:
  customers:
    # will always generate the same value for the same seed
    first_name: fake.seed_instance(_['first_name']) or fake.first_name()
faker_config:
  # IMPORTANT: `fake` and `Faker` names are only available if faker_config is defined.
  locale: en_US

https://faker.readthedocs.io/en/master/index.html#seeding-the-generator

Originally posted by @ReubenFrankel in #2598 (comment)