Merge branch 'settings-dropdown-permissions' into 'master'

Fix displaying of project settings links the user cannot access.

## What does this MR do?

It fixes the Project Settings dropdown displaying project settings links that the user cannot actually access.

## Are there points in the code the reviewer needs to double check?

I've tested combinations I can think of, feel free to mess around with and see if it breaks?

## Why was this MR needed?

Users were seeing links in the Project Settings dropdown that they shouldn't have seen, if they clicked them they would be shown permission errors.

## What are the relevant issue numbers?

#18294 

## Screenshots (if relevant)

Users without any permissions:

![Screen_Shot_2016-06-10_at_10.41.27_AM](/uploads/b70ca18a36b5f774b85694d8f1728882/Screen_Shot_2016-06-10_at_10.41.27_AM.png)

Guest members of the project:

![Screen_Shot_2016-06-10_at_10.48.36_AM](/uploads/a37986b4daa789063661c2fa8cf59d43/Screen_Shot_2016-06-10_at_10.48.36_AM.png)

Full permissions:

![Screen_Shot_2016-06-10_at_10.41.57_AM](/uploads/4c5cc97962e69a1a72ee8e237591ec22/Screen_Shot_2016-06-10_at_10.41.57_AM.png)

cc: @dzaporozhets @annabeldunstone @jschatz1 

See merge request !4599