HomeElementl

[3/n init_resources] Resource initialization refactor

Description

[3/n init_resources] Resource initialization refactor

Summary:
This diff refactors the existing code path for resource initialization.

  1. Makes various top level args Noneable on the resource initialization manager.
  2. Adds a new config wrapper around resource config.

Test Plan: Changed tests to reflect new resource config wrapper.

Reviewers: sandyryza, alangenfeld, max

Reviewed By: alangenfeld

Differential Revision: https://dagster.phacility.com/D6513