[Feature] Calendar widget

## Summary

A calendar widget is a time grid. It'll be useful for showing events, schedules, etc. It's especially useful for teams that deal with deadlines like e-commerce companies, content creation companies, etc.

Features:
1. Ability to move events around
2. Ability to drill down to hour level, day level, week level, month level, year level
3. Creating events by selecting the time period

References:
https://fullcalendar.io/
https://github.com/nhn/tui.calendar
https://github.com/jquense/react-big-calendar

[Front conversations](https://app.frontapp.com/open/top_5blzg)