Tools menu and EffectTypeTool

- Also add a 'Nyquist Prompt' to the Tools Menu.
- Currently it is the same as the Effects Nyquist Prompt.
- Chains moved into the Tools prompt.

include/audacity/EffectInterface.h

@@ -55,7 +55,8 @@ typedef enum EffectType
    EffectTypeHidden,
    EffectTypeGenerate,
    EffectTypeProcess,
-   EffectTypeAnalyze
+   EffectTypeAnalyze,
+   EffectTypeTool,
 } EffectType;
 
 class ShuttleParams;