Wavefront Proxy 15.1 [GA Release]

What's Changed

• Cherry-pick proxy-15.1 release commits by @jb002109 in #917
  • Integrate read-only bloom filter sampling for metrics (US1080317)
  • Sampling preprocessor rules support
  • Fix WF proxy histogram bug (DE669934)
  • Add BeatsParser field length checks (US1106371)
  • Fix unbounded zlib inflate / recursive nesting in compressed frames (US1106371) — security hardening

Full Changelog: wavefront-14.0...wavefront-15.1