Add field properties to object model

[leonhard-s]

Currently most data received through the object model is only available through Ps2Object.data, which is a named tuple containing the original data received.

However, all commonly used data should also be available through class @property-s. The named tuple is only for reference when making requests.

Some thoughts/tentative guidelines:

• The property should return the most intuitive type possible (i.e. datetime.datetime for timestamps, seconds as float for any durations, etc.)
• The docstring must include the way the data was generated

Example:

# auraxium.ps2.Character class

@property
def playtime(self) -> float:
    """Return the character's playtime in hours.

    This uses :attr:`Character.data.times.minutes_played`, divided
    by 60.
    """
    return self.data.times.minutes_played / 60.0

[leonhard-s]

I ended up implementing a fallback __getattr__ hook to Ps2Object to fall through to the data class for attributes and added type hints to include these attributes in the regular object's IntelliSense (21e7e6e).

This is slightly redundant, but also allows us to rename and reorganise attributes in the main classes as we desire (e.g. prestive_level being renamed or aliased to asp_rank).