feat: upload br encoding to asset canister

[sesi200]

Description

Asset synchronization now not only uploads identity and gzip as encodings for MIME types text, js, and html, but also br encoding.

Fixes SDK-1604

How Has This Been Tested?

Added e2e

Checklist:

• [x] The title of this PR complies with Conventional Commits.
• [x] I have edited the CHANGELOG accordingly.
• [ ] I have made corresponding changes to the documentation.