Add "GitLab Team Member" badge to user profile

What does this MR do?

See #213269 (closed) and #212259 (closed)

This MR adds a "GitLab Team Member" badge to user profiles to help contributors identify when they are communicating with a "GitLab Team Member".

There is currently a pretty lengthy discussion happening about how the backend should be implemented and how a "GitLab Team Member" should be determined. See here: !28837 (comment 328910484). Moving forward with the frontend as it is currently behind a feature flag and backend does not block adding the badge to the frontend.

Screenshots

Page	Before	After
User Profile
User Profile Mobile

Local Testing

1. Enable :gitlab_employee_badge feature flag.
   • bin/rails console
   • Feature.enable(:gitlab_employee_badge)
2. In lib/gitlab.rb change self.com? to return true

Note: You may need to run gdk restart because of the caching on app/models/user.rb

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team