Follow-up: Display banner warning admin when the licensed user count has been exceeded

Summary

This is a followup from https://gitlab.com/gitlab-org/gitlab/-/issues/215959/

Tasks:

• We are currently popping a banner in the admin pages which cannot be dismissed. Remove this banner completely.
• Ensure the Users over license Admin panel contains the overage message and is not removed until a license covering the overage is uploaded
• Copy changes within the Users over license and Users in license components.

UX Designs

Please refer to the designs in this issue: https://gitlab.com/gitlab-org/gitlab/-/issues/215959/

Additional reference

https://gitlab.com/gitlab-org/gitlab/-/issues/215959#note_384792239

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/cc @esybrant