message: refactor: Introduce execute_function alias
diff: @@ -21,9 +21,14 @@ namespace fizzy
  struct ExecutionResult;
  struct Instance;
  +/// Function representing WebAssembly or host function execution.
  +using execute_function = std::function<ExecutionResult(Instance&, const Value*, int depth)>;
  +
  +/// Function with associated input/output types,
  +/// used to represent both imported and exported functions.
  struct ExternalFunction
  {
  - std::function<ExecutionResult(Instance&, const Value*, int depth)> function;
  + execute_function function;
  FuncType type;
  };
  @@ -113,7 +118,7 @@ struct ImportedFunction
  std::string name;
  std::vector<ValType> inputs;
  std::optional<ValType> output;
  - std::function<ExecutionResult(Instance&, const Value*, int depth)> function;
  + execute_function function;
  };
  /// Create vector of ExternalFunctions ready to be passed to instantiate.
  