[ECS] Add Inventory component, re-implement player inventories

[dyc3]

• add missing field preventing build, format
• add Inventory ECS component
• add cursor_item fields, getters, setters to Client
• add new_with_title to Inventory instead of using an Option
• add Inventory component to client entities when they connect
• add system update_player_inventories

This does not implement opening other inventories yet, planning to do that in a follow up PR.

The idea here is to have an Inventory component that can be used for all inventories. If you want a chest to have an inventory, give the corresponding block entity an Inventory. If you don't want any inventory update systems to run, simply don't give clients a player inventory.

Code used to test

use bevy_ecs::prelude::*;
use bevy_ecs::schedule::ShouldRun;
use valence_new::client::Client;
use valence_new::config::Config;
use valence_new::dimension::DimensionId;
use valence_new::protocol::types::GameMode;
use valence_new::server::Server;

#[derive(Resource)]
struct GameState {
    instance: Entity,
}

fn main() -> anyhow::Result<()> {
    tracing_subscriber::fmt().init();

    valence_new::run_server(
        Config::default(),
        SystemStage::parallel()
            .with_system(setup.with_run_criteria(ShouldRun::once))
            .with_system(init_clients),
        (),
    )
}

fn setup(world: &mut World) {
    let instance = world
        .resource::<Server>()
        .new_instance(DimensionId::default());

    let id = world.spawn(instance).id();
    world.insert_resource(GameState { instance: id })
}

fn init_clients(mut clients: Query<&mut Client, Added<Client>>, state: Res<GameState>) {
    for mut client in &mut clients {
        client.set_instance(state.instance);
        client.set_game_mode(GameMode::Creative);
    }
}