Remove children macro from prefixed macros

[petrenkonikita112263]

After ... xwikisas/xwiki-pro-macros#220 and completed migration children macro named as confluence_children

[raphj]

Hi,

I'm afraid we went the other direction with xwiki-pro-macros#220. our children macro doesn't support all the parameters that a children macro migrated from Confluence may have.

Basically, children and confluence_children happen to have the same name and similar functionality, but they are not the same.

More generally, we intent to, more and more, name confluence bridge withe a confluence_, and not the opposite. That's because we can't decide what a Confluence macro will do, how and its name.