Add a bunch of hardware tests

Add the audio/atrac/headerfields and audio/audiocodec/at3errors tests
Add the audio/audiocodec/context test
Add the utility/savedata/noupdate and initstatus tests

headerfields already passes: SetData's end sample limit and a sample
offset of 0 counting as a frame match hardware.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

test.py

@@ -138,8 +138,11 @@ tests_good = [
   "audio/atrac/setdata",
   "audio/atrac/sas",
   "audio/atrac/c0mono",
+  "audio/atrac/headerfields",
   "audio/audiocodec/basic",
   "audio/audiocodec/at3param",
+  "audio/audiocodec/at3errors",
+  "audio/audiocodec/context",
   "audio/mp3/checkneeded",
   "audio/mp3/getbitrate",
   "audio/mp3/getchannel",
@@ -519,6 +522,8 @@ tests_good = [
   "utility/msgdialog/abort",
   "utility/savedata/autosave",
   "utility/savedata/shutdownstatus",
+  "utility/savedata/noupdate",
+  "utility/savedata/initstatus",
   "utility/savedata/filelist",
   "utility/savedata/getsize",
   "utility/savedata/makedata",