Adding Confidential and Internal to customer data definition

Why is this change being made?

To improve clarity and transparency on the definition of Customer Data. Currently, Private is used which is a label that can be applied to Projects, Groups, Sub-Groups, and Profiles. As part of this MR, we're including "Confidential" as that applies to Issues and Epics and "Internal" which applies to internal comments/notes.

Note: Original MR. Was behind a few commits behind and the file had moved so created this one and will close the original.

Author Checklist

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• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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