I'd like to use ShouldMatchApproved for binary data - in my scenario, comparing a generated PDF file to a known good file. Attached is a PR to make ShouldMatchApproved support byte arrays.

Considerations:

• Proper message to be displayed when data does not match? Now it just writes "does not match".
• Use existing builder configuration? Now it ignores string-specific settings - case sensitivity, scrubber, line endings.
• Default extension is still 'txt' but probably should be 'dat'. How to support this with current infrastructure? Change default file extension to null, then set to 'txt' or 'dat' within ShouldMatchApproved method?
• Should diff launcher be used? Currently yes.
• Support for Stream rather than just byte[]? Currently no.
• What tests need to be included for this?