Remove the Security Manager New badge

What does this MR do and why?

The Security Manager role went GA in 19.1 and we are on 19.5, so the promotional "New" badge and its "Security Manager role now available" popover are stale.

• Deleted security_manager_new_badge.vue and its spec.
• Removed the usage, import and components entry from role_selector.vue and roles_table.vue.
• Dropped the now-unused ACCESS_LEVEL_SECURITY_MANAGER_STRING import and the isSecurityManagerRole method, since the badge was their only consumer.
• Folded Security Manager back into the describe.each(standardRoles) loop in the roles table spec. It had been filtered out only because the New badge rendered a GlBadge and tripped the "does not show custom role badge" assertion.

The promotional banner half of this was already removed when it was reverted in July, so the badge was all that remained.

Approved by product for this milestone in #601418 (closed).

How to set up and validate locally

yarn jest spec/frontend/members spec/frontend/access_level ee/spec/frontend/roles_and_permissions

1401 tests, 0 failures.

References

#601418 (closed)

Related cleanup: #584144 (closed)

Screenshots or screen recordings

Before	After

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