add a `validate=False` option for `graph_objects` and `px` figures

There's already an issue outlining the effects graph_object validation has on plot generation time. Users can bypass this performance hit by replacing the graph_objects with dict and then display the plot with plotly.offline.iplot(fig, validate=False) or if they are creating graphs in Dash, they can forgo the plotly.py library altogether and just use a dict in their Graph component's figure argument.

This solution can greatly improve the performance of Dash apps but it means that Dash users with expensive graphs have to choose between using px/plotly.py's update methods and optimally fast code.

I wonder if a way to turn off validation, especially in Dash apps, would help Dash users get the best of both worlds.

cc @matthewchan15

issue #1052 と、graph_objects および px の既存の figure 生成パスを確認し、その後、offline.iplot と関連する figure consumer の前に検証がどのように適用されているかを追跡します。これらの API 全体で validate=False オプションがどのように機能すべきかを、Dash のユースケースも含めて定義し、検証を無効にすることで対象のパスが改善され、通常の検証ありの動作が変わらないことを確認します。