Feature: Implement 'Public Holidays widget'

[Zalmez]

As a user, I want to be able to add a 'Public Holidays Widget' to my dashboard.

Functionality:
Displays public holidays of configure country based on https://kayaposoft.com/enrico/json/v3.0/openapi/Enrico-Service-3.0.json

Acceptance Criteria:
User must be able to select a country based on supported countries
User must be able to select if they want to see the current day, month, year or for a date range
Default should be for the current month