Aid the creation of valid calendars.

[niccokunzmann]

Some properties are required, others optional, some are strictly typed.

In order to start creating valid calendar times with many other features included, this issue proposes adding a new() method to the Component classes.

Example:

>>> event = Event.new(start=date(2025, 10, 11))
>>> print(event.to_ical().decode())
BEGIN:VEVENT
DTSTART;VALUE=DATE:20251011
UID:<randomly-generated-uuid4>
DTSTAMP:<now>
END:VEVENT
>>> calendar = Calendar.new(components=[event])

Benefits:

• The calendar can create a valid calendar from the start
• E.g. DTSTART is required IF the calendar has no method -> we can run checks on the whole object structure
• We can use getters and setters to set the values, providing additional verification without code duplication
• Generation and setting of default values is still possible
• We do not deprecate or interfere with the minimal way of event = Event()

See also:

• Mandatory properties are neither enforced nor set to a default #596
• unique identifier must be included in VEVENT, VTODO, and VJOURNAL #315
• Enhancing icalendar through attributes #662
• (Auto) fixing invalid icalendar (components) #536
• Strict mode for reading/writing ical #548
• Guide the creation of rfc compatible components #817