Replace scopedProperties, which only WalletConnect v2 supports, with a custom
JSON-RPC method that WalletConnect v1 (Pera Connect, Defly Connect) can also
carry, and that could later refresh empty signatures without a reconnect.

- The method is requested in optionalNamespaces, so wallets that don't
  support it still approve the session, and only called if approved
- It's called right after connect with a 30s timeout and never holds up the
  connection; late responses are discarded if the session or network changed
- Restored and updated sessions keep the store's empty signatures; a new
  session starts without any until the wallet answers
- Add BaseWallet.applyEmptySignatures() for adapters to apply a wallet's
  { address: base64 } response consistently