Translated effect name and description in many places in Effect.cpp...

... including titles of dialogs,
messages,
About sub-menu of the Manage button,
long-form names of Undo items (in history view),
message for why command is not allowed when there is no selection

Also one place in Effect Rack code but it's commented out

src/effects/audiounits/AudioUnitEffect.cpp

@@ -892,7 +892,8 @@ wxString AudioUnitEffect::GetVersion()
 
 wxString AudioUnitEffect::GetDescription()
 {
-   return wxT("N/A");
+   /* i18n-hint: Can mean "not available," "not applicable," "no answer" */
+   return XO("n/a");
 }
 
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