Allow Delegated Access or Project-Scoped View for Xray Usage Monitor

The current implementation of the Xray Usage Monitor restricts access exclusively to users with Jira Admin permissions.

Propose enhancing the Usage Monitor feature with one or both of the following capabilities:

1. Delegated Access - Allow Jira Admins to grant read-only access to the Usage Monitor to selected users or groups (via a toggle or user-picker).
2. Project-Level Usage View - Introduce a scoped view of usage metrics limited to the user’s permissions, allowing them to see usage for the projects they have access to.