Add APIs for encoding and decoding key configs for wire transmission

[chris-wood]

Closes #7.

This lets applications transfer the key config over the wire from gateway to client.

[chris-wood]

@dajiaji it's not clear to me why the Node.js test is failing -- do you happen to know?

[dajiaji]

@chris-wood Could you update your dnt library in import-map.json to the latest (v0.33.1) and try again?

[chris-wood]

@dajiaji thanks -- that seemed to yield a different error now! Please see below when you have a moment:

found 0 vulnerabilities
[dnt] Building project...
[dnt] Type checking...
src/deps/deno.land/x/hpke@v0.18.2/src/kems/dhkemPrimitives/x25519.ts:1:33 - error TS2307: Cannot find module '@noble/curves/ed25519' or its corresponding type declarations.

1 import { ed25519, x25519 } from "@noble/curves/ed25519";
                                  ~~~~~~~~~~~~~~~~~~~~~~~
src/deps/deno.land/x/hpke@v0.18.2/src/kems/dhkemPrimitives/x448.ts:1:29 - error TS2307: Cannot find module '@noble/curves/ed448' or its corresponding type declarations.

1 import { ed448, x448 } from "@noble/curves/ed448";

[dajiaji]

@chris-wood It seems to be due to the fact that dnt's npm support is not complete. Could you apply the following change to dnt.ts?

-  typeCheck: true,
+  typeCheck: false,

[chris-wood]

@dajiaji that did it -- thank you! 🙏

[dajiaji]

No problem. Sorry to bother you with deno-specific problems.

[dajiaji]

It seems to me that it would be better to make hpke-js disclose the KEM classes directly.