Add group-level deployment frequency charts

Nathan Friendrequested to merge
nfriend-add-group-level-deployment-frequency-graph into master

What does this MR do?

Adds group-level deployment frequency charts to the Group > Analytics > CI/CD page.

These charts are the equivalent of the project-level deployment frequency charts.

Screenshots

Before After
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Related to #291748 (closed)

Edited by Nathan Friend

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