Add fallback decoding for asgi headers

[rocky-ken]

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Description

Add fallback decoding for asgi headers if utf-8 decoding throws an error.

Duplicate of PR 1713 to hopefully get it over the finish line

Fixes #1814 Fixes #1478

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Test it in asgi

Does This PR Require a Core Repo Change?

• [x] No.

Checklist:

See contributing.md for styleguide, changelog guidelines, and more.

• [x] Followed the style guidelines of this project
• [ ] Changelogs have been updated
• [ ] Unit tests have been added
• [ ] Documentation has been updated