MR Analytics: Throughput MVC
### Problem
Throughput is an important metric for many organisations to judge productivity.
### Proposal
- Create a set of features that let users understand recent throughput at the **project** level
- Understand how this fits into broader the broader MR workflow
- Gather feedback from users and dogfooding to refine vision and direction (https://gitlab.com/gitlab-org/gitlab/-/issues/229823)
epic