Create Calendar configuration Custom metadata setting

[marsson]

As a system administrator I would like to have a custom metadata setting so that I could configure a calendar.

Acceptance criteria and technical description:
The new custom metadata setting should have the following custom fields:

1. Implementation Class(text 80) (help text) apex class that implements the interface IF APEX SETTING IS USED.
2. Calendar Title (Text 40) (help text) The title that will be displayed on the calendar component
3. Today Color (color or Hexa code for HTML color) -> Can set validation rule if inspired/use a picklist for 10 colors.
4. Icon: (Text 40) help text -> Name of system Icon to be displayed
   5)Object Api Name (Text 80) help text -> API name of the object this calendar will be related to.

In this user story you will have to create lookup fields on the Calendar Date and Calendar date ranges Metadata types for them to be children objects from Calendar configuration.