VSA & VSD - "Flow Distribution" (Aka Task by Type) - add widgets with work type distribution

Problem to solve

Executives want to know if money was spent on innovation or on KTLO.

This is Dogfooding feedback.

Proposal:

Adding a new "Flow Distribution" widget with pie chart:

1. Select data - Issues or MRs.
2. Both open and closed work items.
3. Breakdown label - when adding the widget the user can select scoped labels (e.g. ~type::*), as the data breakdown. Each slice represents a percentage of work items - (e.g. ~bugs 26.3% 👆)
4. Filters - user can filter the chart per group/project, and per label.
5. For this MVC, monthly aggregation only.
6. For this MVC, present only the top 10 slices.
7. Value labels are presented in percent.
8. Order slices according to their size

Related issues

• The pie chart of the overview widget.
• VSA: Usability improvements for "tasks by type"... (&7412)

JTBD

• As Software leader I need to balance type of work (features, maintenance, bugs) so I my team can have a healthy prioritization method and to response quickly for changing needs.
• As Software leader I want to understand how work is spent and if it's aligns with business priorities.

Acceptance Criteria

1. Select filtering by the ~type::*.
2. The chart will shows a cumulative count of issues and merge requests breakdown to typebug typefeature typemaintenance typeignore

(Pre-build chart tool that wires into GitLab labels.)