Add Slack-like emoji status

[dohsimpson]

I want to add a slack-like status (emoji) next to the profile icon, to support some basic status, e.g.

🤒: sick
✈️: traveling
🆘: mental health

The reason to is provide relief for those situations where we unfortunately cannot complete the habits due to things outside of our control, and not feel guilty for it.

After setting a status, the calendar and habit streak will display the status icon for the affect dates, indicating that you take into the special situations into consideration. e.g. not able to complete any habits today is ok because you are 🤒.