[FR] Time tracking plugin

### Description

An interface wherein one can
- provide an quick scroll-able interface wherein one can see a list of active projects. A project may have a task in progress, or have no tasks in progress.
- Selecting a project, should take one to a view where one may select/toggle/start/stop an tasks of the project. A project with an ongoing task is one that is currently being worked on. This interface allows the user to manually, track the time, its start time and its end-time.
- perhaps export activity to a calendar/ical-planner, optionally record a comment on the task.
- provide an interface where on can create a list projects (perhaps import this from a task planner/scheduler) that may optionally have a hierarchy.
- provide an interface where on can create tasks in each projects (perhaps import this from a task planner/scheduler)
- provide an overview interface/view to select a date/time and visualize the allocation of time per project in a day-range/week-range/month-range/year-range , either as a pie chart-or stacked-bar chart.
- The hierarchical-ness of projects, allows for letting the sum of all tasks of one project be accounted as task of another, accumulating the time.
- provide an edit-view to modify configured projects/tasks.
- provide an edit-view to modify old activity records and maybe also corresponding ical-planner.
- allow for a configurable reminder such as off/hourly/half-hourly/15min like notification/reminder to remind user to record entry of current activity.
- allow for import/export to/from some standard format ical, csv, xlsx etc.
- Optionally, allow for other features such as unbilled/fee/rate/billing/invoicing
- Optionally, allow for archiving completed no-longer worked on projects, and deleting a project, deleting a projects activity.

### Impact

Users who need a time tracking system.
One can't improve what one does not measure.
A time tracker lets one be honest to oneself about how long some tasks take, and also time lost between tasks,

### Additional Context

Maybe similar to
ex: https://github.com/kromitgmbh/titra/