Return CalendarRules if present in the in-memory database when retrieving Calendar entity

[jordimontana82]

Is your feature request related to a problem? Please describe.
At the minute, CDS / CRM returns calendarrules entities / attributes when retrieving a Calendar entity without requesting them explicitly. This feature will return any calendar rules (if any) when retrieving a Calender entity record.

Describe the solution you'd like
A clear and concise description of what you want to happen.

Describe alternatives you've considered
At the minute, a workaround involves adding custom execution mocks to overcome this issue.

Additional context
More info in this issue #528