* Add multi-attribute aliases to some packets, for user convenience.
* Add support for writing PlayerListItemPacket.
* Add 'fields' attributes to manually-read/written packet classes,
implementing 'field_string' where appropriate to allow enable the
default __repr__ implementation.
* Modify data constructors where appropriate so that __repr__
implementations match their constructor protocols.
* Improve comments on type aliases within packet classes.
* Add/modify tests to cover the new functionality.
Remarks: I chose to implement an angle between 0-360 degrees as opposed to -180 - 180. linear transformation, the maths was far simpler converting an UnsignedByte into positive values instead of a Byte into negative and positive
This commit introduces two backward-incompatible changes which may break
existing code:
(1) `networking.packets.clientbound.play.SpawnObjectPacket.EntityType'
is no longer accessible as an attribute of the the `SpawnObjectPacket'
class: the values now depend on a `ConnectionContext`, and must be
accessed through an instance, or using `SpawnObjectPacket.field_enum'.
See the text of the `AttributeError` raised from the descriptor for
`SpawnObjectPacket.EntityType` for the full details.
(2) For some subclasses of `networking.types.Type', it is necessary to
call the methods `read_with_context' and `send_with_context' instead of
`read' and `send', supplying a `ConnectionContext' for those data types
- currently only `Position` - whose layout depends on it.
Information gathered from https://wiki.vg/Protocol_version_numbers.
Due to some difficulties the change from "sound_id" to "sound_name" and
the re-implementation of "sound_category" in the packet may be off by
some protocol versions.
