Separate administrator and user settings for project integrations

What does this MR do and why?

• Separates administrator settings at the instance level from user settings at the group or project level in Project integration management
• Moves user settings to Project integrations
• Adds notes to both pages and reworks the introduction for Project integrations

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.