Remove aes-crypto-utils.js from media and use common API to avoid redundent layer of abstraction

Summary: This differential removes web/media/aes-crypto-utils.js file and changes relevant files to make direct calls to lib/media/aes-crypto-utils.js API. This change was done in response to one of the comments to parent differential

Test Plan: 1. Run flow. 2. Ensure that CI passes (it runs jest)

Reviewers: bartek

Reviewed By: bartek

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8602