dt_push_post_args filters are defined inconsistently.

[gthayer]

The filter dt_push_post_args is used inconsistently, where External Connections are using 3 variables with the 3rd being the class object, while Internal Connections have 4 variables with the 4th being the class object.

I believe we should add the missing $args value in the external connections call, and set the class object as the 4th value to match the internal connections call.

These should be consistant because filters looking for 4 values will get Uncaught ArgumentCountError: Too few arguments errors.

PR incoming...