Extra component "form inputs" is not accessible from the sidebar menu

[dizco]

Issue type

I'm submitting a ... (check one with "x")

• bug report
• feature request
• question about the decisions made in the repository

Issue description

Current behavior:

The page http://akveo.com/ngx-admin/#/pages/extra-components/form-inputs does not have a menu item associated with it under Extra Components. I believe this has been introduced by #1911

Expected behavior:

The page should have it's menu item. otherwise almost nobody will see it :)

Steps to reproduce:

Related code:

Other information:

npm, node, OS, Browser

Angular, Nebular
ngx-admin 3.0.0