[Fixed] add dBW, decibel watts

[MattEttus]

• [N/A] Closes # (insert issue number)
• [N] Executed pre-commit run --all-files with no errors
• [Y] The change is fully covered by automated unit tests
• [N/A] Documented in docs/ as appropriate
• [Y] Added an entry to the CHANGES file

fixed the previous one which was against the wrong branch and had omitted a close paren. This change adds dBW, decibel Watts