Add wire format capability negotiation extension

[bifurcation]

A notable omission from the Capabilities / RequiredCapabilities objects in RFC 9420 is the ability to negotiate support for new wire formats. This document should address that deficiency. What we would need is a supported_wire_formats extension, where:

• The content of the extension is WireFormat wire_formats<V>;
• The extension can appear in LeafNode and GroupContextExtensions
• The semantic in LeafNode is "here are the new WireFormats I support"
• The semantic in GroupContextExtensions is "here are the WireFormats that are required for this group"