Pass $instance to the "widget_text" filter

[Viper007Bond]

I'm trying to conditionally change the content of the text widget. I'm storing whether I need to modify the content or not in the widget's settings by using the widget_update_callback filter and adding a key to the array. However I cannot access the reset of the widget's settings (where my new key is) from within the widget_text filter.

Attached patch passes $instance to the widget_title and widget_text filters for increased flexibility.

(In [11792]) Pass the widget instance as context to the widget_title and widget_text filters. Fixes #10573 props Viper007Bond.