This PR allows configuring the intensity of code fade applied to unused
code (relates to #4785).
_Note: Right now I included it as a top level config which might be a
little out of place (but is easiest to instrument). Open for suggestions
on where else it would be better suited for._
_Note 2: I am unfamiliar with the codebase. Feel free to either close
this PR and re-implement in a better way or suggest high level changes
if I'm approaching anything wrong :)._
Release Notes:
- Added `unnecesary_code_fade` setting to control how strongly to fade
unused code.
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Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
5c0d800b21