[MR Widget V2] Add info popover

Summary

This issue is very similar to #361562 (closed), except it's for the MR Widget V2.

Add an info popover with the text below. The tooltip will link to this page: https://docs.gitlab.com/ee/user/application_security/#ultimate

Implementation plan

• frontend Add the popover to the https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/app/assets/javascripts/vue_merge_request_widget/extensions/security_reports/mr_widget_security_reports.vue.

Similar implementation can be found in the following MR: #361562 (closed)