CommandSearch: Begin basic functionality (prints filename of result)

cli/commandsearch.h

@@ -8,10 +8,7 @@ class CommandSearch : public Command
   public:
 	using Command::Command;
 
-	int handle(QStringList arguments) override
-	{
-		return 23;
-	}
+	int handle(QStringList arguments) override;
 };
 
 #endif // COMMANDSEARCH_H