Add "Bring Your Own Wallet" (BYOW) support #77
Description
Done Criteria
Rather than rely on an embedded session key or private key, allow the user connect their wallet.
Why Important
This is critical for having something public (e.g., pin.filecoin.cloud) that is running on mainnet. In a mainnet configuration, "real funds" are at play, and likely don't want to support a wallet that anyone can use to make storage requests with.
In addition, showing wallet integration like https://demo.filecoin.services/ is a more complete end-to-end dApp example with filecoin-pin.