fix: Handle transactions after NAJ update to v4.0.x for WalletConnect

[kujtimprenku]

Description

After the update of wallet selector to use NAJ v4.0.x the wallet-connect signAndSendTransaction(s) has stopped working because the type of the value of tx.encode() has changed from Buffer to Uint8Array since NAJ v3 the [email protected] update.

WalletConnect uses formats and encodes the payload and this handles the Buffer and Uint8Array differently.

This PR adds support to handle the result returned from a wallet that uses latest version of NAJ (Uint8Array) and still keeps support for the old versions (Buffer).

I have also updated the web-examples of WalletConnect to add support for the latest version(s) of NAJ:
reown-com/web-examples#702

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Type of change.

• FIX - a PR of this type patches a bug.
• FEATURE - a PR of this type introduces a new feature.
• BUILD - a PR of this type introduces build changes.
• CI - a PR of this type introduces CI changes.
• DOCS - a PR of this type introduces DOCS improvement.
• STYLE - a PR of this type introduces style changes.
• REFACTOR - a PR of this type introduces refactoring.
• PERFORMANCE - a PR of this type introduces performance changes.
• TEST - a PR of this type adds more tests.
• CHORE - a PR introduces other changes than the specified above.

[pivanov]

What do you think about this approach?

[pivanov]

let signatureData: Uint8Array;

if (result instanceof Uint8Array) {
  // This will handle both Buffer and Uint8Array since Buffer is a subclass of Uint8Array
  signatureData = result;
} else if (Array.isArray(result)) {
  signatureData = new Uint8Array(result);
} else if (typeof result === "object" && result !== null) {
  signatureData = new Uint8Array(Object.values(result));
} else {
  throw new Error("Unexpected result type from near_signTransaction");
}

return nearAPI.transactions.SignedTransaction.decode(
  Buffer.from(signatureData)
);

We can make the helper method to handle the transaction and use it in the results.map below.

[kujtimprenku]

@pivanov Thanks for the review. I added a new helper function using the suggested code above.