Add manage roles link to roles dropdowm

What does this MR do and why?

Add manage roles link to access level dropdown in members table and invite modal.

Also fixes LDAP footer button which was shown with a scrollbar.

Issue: #437593 (closed)

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Simulate SaaS
2. Create a namespace and apply the Ultimate license to the namespace
3. Visit http://localhost:3000/groups/#{group_name}/-/group_members and click Invite members
4. Verify the Manage roles button is visible in the footer of the access level dropdown and that clicking it takes you to http://localhost:3000/groups/#{group_name}/-/settings/roles_and_permissions.