Replace calls to %v for error values in fmt.Errorf with %w

[moskyb]

Description

The %w formatting verb has been available forever^{[citation needed]} now, and it's frustrating to use errors.Is, expecting to find a wrapped error, only to find out that a call to %v in a fmt.Errorf call (instead of %w) has eaten all of the error decoration.

This PR casts a wide brush across the codebase, and attempts to replace many (most? all?) uses of %v for errors in calls to fmt.Errorf with %w, properly wrapping those errors

Testing

• Tests have run locally (with go test ./...). Buildkite employees may check this if the pipeline has run automatically.
• Code is formatted (with go fmt ./...)