Add networked-dom-v0.2 protocol (#54)

[MarcusLongmuir]

Resolves #54

This PR adds a new iteration of the Networked DOM Protocol, networked-dom-v0.2 as a progression from networked-dom-v0.1.

This new protocol is binary-based and is based on uvarints, varints, and UTF-8 strings.

This new version of the protocol addresses multiple issues:

• The protocol now supports representing multiple users' views with a single connection - allowing multiplexing/fan-out proxies
• The protocol is binary-based rather than JSON-based which speeds up encoding by ~3x, decoding by ~2x, and reduces encoded size by ~3x.
• The protocol adds support for batching multiple diffs together which avoids a client seeing/rendering a partial set of changes to the DOM (e.g. only some attributes of an animation element updating).

This PR adds support for networked-dom-v0.2 to the @mml-io/networked-dom-document library which now supports both networked-dom-v0.2 and networked-dom-v0.1 protocols for incoming WebSocket connections.

The NetworkedDOM class has been overhauled to support both protocols, and has had significant optimisations done to it in the process, including doing a single stringifying/encoding of messages for multiple clients for most mutations that affect all clients.

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What kind of changes does your PR introduce? (check at least one)

• Feature
• Refactor

Does your PR introduce a breaking change? (check one)

• No

Does your PR fulfill the following requirements?

• All tests are passing
• The title references the corresponding issue # (if relevant)

[github-actions]

🪓 PR closed, deleted preview at https://github.com/mml-io/mml/tree/gh-pages/pull/210/