Create conventions for T get(K keyLike) variants

[supersaiyansubtlety]

It's been discussed a couple times in PR comments, I propose the following conventions:

// net/minecraft/state/State

@Nullable
public <T extends Comparable<T>> T get(Property<T> property) {
    Comparable<?> comparable = (Comparable<?>)this.entries.get(property);
    return comparable == null ? null : property.getType().cast(comparable);
}

public <T extends Comparable<T>> T getOrThrow(Property<T> property) {
    Comparable<?> comparable = (Comparable<?>)this.entries.get(property);
    if (comparable == null) {
        throw new IllegalArgumentException("Cannot get property " + property + " as it does not exist in " + this.owner);
    } else {
        return property.getType().cast(comparable);
    }
}

public <T extends Comparable<T>> Optional<T> getOrEmpty(Property<T> property) {
    return Optional.ofNullable(this.get(property));
}

public <T extends Comparable<T>> T getOrDefault(Property<T> property, T defaultValue) {
    return Objects.requireNonNullElse(this.get(property), defaultValue);
}

I've seen getOrNull suggested for the first variant.
I prefer get because I think one of them should be just get, and this matches java.util.Map::get.

If only one single-param variant is present, I think get should be used regardless of which variant it is (getOrDefault should always be getOrDefault).

Note that I'm not suggesting a convention for differentiating between methods that get values based on various different key-likes, such as Identifier id and int rawId, which I don't think should be generalized into a convention.