api: Add support for 'compacting' components

[zml2008]

Closes GH-114

This ports the implementation of component compacting over from the original Kotlin provided by @CrushedPixel (see that here)

While this component optimization is expensive enough that it shouldn't be used on every message sent, it can be useful for ensuring components of unknown origin (such as loaded from a configuration, or built from multiple sources) are as compact as possible before being sent to users.

Some things to discuss:

• The name: Does compact make sense, or should we use something else like optimize or pack?
• Should a setting be added to the serializers (mainly the Configurate serializer, but possibly others) to auto-compact when loading?

[octylFractal]

kewl, maybe call it optimize if you're gonna call it that internally anyways