[MICROBA-1179]
- Continue renaming/removal of code referring to the Certificate "white list".
The Certificates Django app `CertificateWhitelist` model is going away in an effort to make our codebase more inclusive. It is being replaced
with the `CertificateAllowlist` model. This PR continues to replace references to the Certificate "whitelist" with "allowlist" wherever
possible. There should be no change in functionality, nor are there any changes in appearance.