Merge #17482: util: Disallow network-qualified command line options

900d8f6f70 util: Disallow network-qualified command line options (Russell Yanofsky)

Pull request description:

  Previously these were allowed but ignored.

  This change implements one of the settings simplifications listed in #17508. Change includes release notes.

ACKs for top commit:
  laanwj:
    ACK 900d8f6f70

Tree-SHA512: ab020a16a86c1e8ec709fbf798d533879d32c565eceeb7eb785c33042c49c6b4d1108c5453d8166e4a2abffc2c8802fbb6d3b895e0ddeefa8f274fd647e3c8ad

doc/release-notes.md

@@ -104,6 +104,13 @@ Wallet
 Low-level changes
 =================
 
+Command line
+------------
+
+Command line options prefixed with main/test/regtest network names like
+`-main.port=8333` `-test.server=1` previously were allowed but ignored. Now
+they trigger "Invalid parameter" errors on startup.
+
 Tests
 -----