[FR][UI] Aggregate listing of tracked times

[noerw]

Currently, the tracked times feature is hardly usable for things like billing, where I need to have an overview of total time spent, ideally across multiple repos.
This time spent metric needs to be filterable by the date the time was logged.

We currently have no GUI for this, but the API provides the needed data via /user/times.
Additionally, it would be nice to have aggregate values per issue, user & repo

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs during the next 2 weeks. Thank you for your contributions.

[noerw]

closing as duplicate / related to #4870