PassEvent fields should be optional but are declared as required

[DriesDeprest]

Problem

The PassEvent class declares three fields as required, but many serializers set them to None because data providers don't always provide this information:

@dataclass(repr=False)
class PassEvent(Event):
    receive_timestamp: float              # Declared as required
    receiver_player: Player               # Declared as required
    receiver_coordinates: Point           # Declared as required
    result: PassResult

Evidence

• receiver_player: Set to None in 13+ serializers (impect, metrica, sportec, scisports, statsbomb, smrtstats, datafactory, korastats, statsperform, wyscout v3)
• receiver_coordinates: Set to None in 6+ serializers (impect, wyscout v2/v3, metrica, sportec, datafactory)
• receive_timestamp: Set to None in 5+ serializers (smrtstats, metrica, statsperform, sportec)

Impact

• Type hints are violated (mypy/pyright would flag errors)
• Misleading API - suggests fields are always available
• Potential runtime errors when code assumes non-None values

Proposed Solution

Make these fields explicitly optional, matching the pattern used in ShotEvent.result_coordinates:

@dataclass(repr=False)
class PassEvent(Event):
    receive_timestamp: Optional[float] = None
    receiver_player: Optional[Player] = None
    receiver_coordinates: Optional[Point] = None
    result: PassResult

This is backwards compatible at runtime but properly reflects the actual data model.

[DriesDeprest]

Similar issue exists for CarryEvent fields. Both end_coordinates and end_timestamp are declared as required but are set to None in multiple serializers:

end_coordinates: Set to None in impect/specification.py:263

end_timestamp: Set to None in impect/deserializer.py:267, wyscout v2/v3, datafactory, korastats, sportec

@dataclass(repr=False)
class CarryEvent(Event):
    end_timestamp: float       # Declared as required
    end_coordinates: Point     # Declared as required
    result: CarryResult

Two possible approaches to fix this:

1. Make them optional (consistent with the PassEvent fix):

   end_timestamp: Optional[float] = None
   end_coordinates: Optional[Point] = None

2. Set defaults when missing - when provider data doesn't include end coordinates/timestamp, fall back to the start values:

   end_timestamp: float = field(default_factory=lambda: self.timestamp)
   end_coordinates: Point = field(default_factory=lambda: self.coordinates)

   Alternative for end_timestamp: Set it to timestamp + 0.1 (or similar small delta) instead of the same value as timestamp, to avoid division-by-zero errors when calculating speed or other time-based metrics (e.g., distance / (end_timestamp - timestamp)). This would represent an instantaneous carry with minimal duration rather than a zero-duration event.

Option 2 might be semantically better since a carry always has an end point (even if it's the same as the start), but Option 1 is more explicit about missing data.