Wavefront Proxy 14.0 [GA Release]

What's Changed

• Proxy 14.0 changes by @joannatk in #915
  • Support Preprocessor Rules set via UI or API
  • Address CVE-2024-47561: Bump Apache Avro to 1.11.4
• README update by @joannatk in #916

Full Changelog: proxy-13.9...wavefront-14.0