Empty fingerprint but no warning if file size between noise and guarantee thresholds

[louis-hildebrand]

If a file has fewer than guarantee tokens, we would generate an empty fingerprint for it. There is currently a warning that informs the user of this when the file has fewer than noise tokens. But if the file has at least noise tokens, it will have an empty fingerprint but no warning will be emitted.

Possible fixes:

• (Probably easier) Emit a warning if the file size is less than guarantee tokens.
• Leave the check as-is but change the fingerprinting engine to generate a non-empty fingerprint. This is possible only if the file has at least noise tokens.