Reconsider proxy system

[leonhard-s]

The current placeholder proxy objects work, but do not supported nested operations. It'd be very neat if they did.

Example for such a currently unsupported interface:

outfit = await ps2.Outfit.get_by_tag('<your_tag_here>', client=auraxium.Client())

# This is now a proxy object, awaiting it would return a list of OutfitMember instances
members = outfit.members()

# The character attribute failed over to the OutfitMember class and this is now a
# SequenceProxy of Character, with the URL dynamically updated in the background.
characters = outfit.members().character()

Supporting this in parallel to the existing syntax (which I would like to keep) either requires a revamp of how proxy objects work, or some decorator-infused Descriptor object that allows accessing the URL used to link these related object types.

[leonhard-s]

Related to proxies:

It would be handy to have an asynchronous lazy-loader for time-insensitive data (such as resolving player names from the ESS stream). It would group requests to the same data type together and eventually send them as a larger query, either triggered by batch size or time passed:

async def get_soon(type_: Type[T], query: Query, max_entries: int = 20, max_delay: float = 30.0) -> T:
    ...

They would remain separate, create a common asyncio event/future, which is then split back up into individual objects to be returned to the respective get_soon callers' futures.

[leonhard-s]

Bumping priority as I am unhappy with the proxy system both for maintainability, performance, and flexibility. Considering deprecation for 0.3.