BP Nouveau: invite group creation step name customization is not applied

[imath]

Since r13156 it looks like the bp_nouveau_group_invites_create_steps() filter callback has no effect on the invite group creation step name. I'm unsure it had once as the filter is defined before the Groups component has set all the built in creation steps.

The filter should be defined after, so that Nouveau can customize the create step name and so could do any BuddyPress plugin.

[imath]

In 13202:

Apply filters to edit Group create steps once all Core steps are set

The 'groups_create_group_steps' has been moved below the code defining all default group creation steps. This move gives more customization possibilities to plugin author than before: they can, like BP Nouveau is doing for the Group invites step, edit the name of all steps as well as their position during the creation process.

Fixes #8609