Hide some UI elements from users that lack admin_security_attributes permission

What does this MR do and why?

Require admin_security_attributes to apply/remove

Require canManageAttributes (can_admin_security_attributes) for:
- "Security attributes" tab on project security configuration page
- "Edit security attributes" action on group security inventory page
- "+ Add attributes" link in group security inventory page

Why? We want to require this permission in order to apply attributes to projects (not just to create/update/delete categories and attributes) - which was discussed in a few places throughout the development of Security Attributes/Context Filtering (&18010), but wasn't clearly defined when I scaffolded these pages (#550478 (closed), #550472 (closed), #550473 (closed)).

References

• Define Security Attributes permissions model (#562417)
• Improve permissions validation for categories a... (#567237)

Screenshots or screen recordings

	Before	After
top-level group developer viewing inventory	can see attributes in the cell, can apply attributes to projects	can see attributes in the cell (once #577049 is fixed), but cannot apply attributes to projects
top-level group developer viewing project security configuration	can see the security attributes tab, can apply attributes to project	cannot see the security attributes tab at all
top-level group maintainer viewing inventory	can see attributes in the cell, can apply attributes to projects	no change
top-level group maintainer viewing project security configuration	can see the security attributes tab, can apply attributes to project	no change

How to set up and validate locally

git checkout mfluharty-gate-applying-attributes-behind-admin-permission
echo "Feature.enable(:security_categories_and_attributes)" | gdk rails c
echo "Feature.enable(:security_context_labels)" | gdk rails c

1. navigate to a top-level group where you are at least a maintainer
2. navigate to => Secure => Security inventory - you should be able to apply security attributes to projects
3. navigate to a project in the group => Secure => Security configuration - you should be able to apply security attributes to the project
4. add a user as a developer in the top-level group, use the admin area to impersonate them
5. navigate to => Secure => Security inventory - you should NOT be able to apply security attributes to projects
6. navigate to a project in the group => Secure => Security configuration - you should NOT be able to see the Security attributes tab

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.