feat: add static uploads API (#148)

This PR adds static methods allowing streaming uploads to the service.
It is integrated with ucanto 0.9.

Essentially the client is "bring your own agent" - it requires an
`issuer` (a `Signer`) and `proofs` (delegated capabilities) to be passed
to each method.

The API is oriented around 3 use cases:

1. Simple and easy to use `uploadFile`/`uploadDirectory` methods that
return CIDs.
2. More advanced APIs that split out DAG creation, CAR creation, storing
and registering uploads.
3. Streaming APIs that have the same split, but cater for uploads of
arbitrary size using streams.

Every method has tests and the [README has extensive examples and API
reference
documentation](https://github.com/web3-storage/w3protocol/blob/777327609cd2c96b2be4e5e8d48e9a45f17b9a7b/packages/upload-client/README.md).

closes #150

Co-authored-by: Oli Evans <oli.evans@gmail.com>

.github/workflows/client.yml → .github/workflows/upload-client.yml

@@ -1,4 +1,4 @@
-name: Client
+name: Upload Client
 env:
   CI: true
   FORCE_COLOR: 1
@@ -28,5 +28,6 @@ jobs:
           node-version: 18
           cache: 'pnpm'
       - run: pnpm install
+      - run: pnpm -r --filter @web3-storage/upload-client run build
       - run: pnpm -r --filter @web3-storage/upload-client run lint
       - run: pnpm -r --filter @web3-storage/upload-client run test