Include replies menu order to `bbp_insert_reply()` improving reply unit tests

[netweb]

We need to include the replies menu_order when creating replies with bbp_insert_reply() for accurate unit testing

[netweb]

In 5889:

Replies: Include replies menu order when creating replies with bbp_insert_reply() improving reply unit tests

See #2843

[netweb]

In 5890:

Tests: Update tests to always include a parent topic for replies

This changeset ensures replies always have a parent topic which in turn ensures each reply is created with an accurate menu_order position.

Fixes #2843

[netweb]

In 5891:

Replies: Remove previous menu_order default from bbp_insert_reply() missed in r5889

Antiprops netweb. See #2843.