feat(wallet): Refactor wallet service for enhanced modularity and clarity

- Abstracted RPC interface to allow dynamic input for connection flexibility.
- Added `signSession` function to retrieve `authSig` efficiently.
- Improved logging and error handling to provide clearer feedback.
- Centralized `authSig` retrieval for better code maintainability.

This refactor ensures the wallet service is more adaptable to varying use cases and improves overall code readability.

src/lib/services/wallet/README.md

@@ -0,0 +1,36 @@
+# `wallet.ts` Service Documentation
+
+The `wallet.ts` service provides utilities for working with the PKPEthersWallet, including connecting and retrieving the authentication signature.
+
+## Dependencies
+
+- `getStoredAuthSig` from `'$lib/services/authWithMetamask/authWithMetamask'`
+- `PKPEthersWallet` from `'@lit-protocol/pkp-ethers'`
+- `createMessage` from `'$lib/services/messages'`
+
+## Variables
+
+- **isWalletConnected**: A boolean flag that keeps track of whether the wallet is currently connected or not.
+
+## Functions
+
+### `connectWallet(pkpPubKey: string, rpcURL: string = 'https://rpc.gnosischain.com/')`
+
+#### Parameters:
+- **pkpPubKey**: The public key used to connect to the wallet.
+- **rpcURL** (Optional): The RPC URL for the connection. Defaults to `'https://rpc.gnosischain.com/'`.
+
+#### Returns:
+- A promise which resolves to an instance of `PKPEthersWallet` if the wallet is successfully connected. If the wallet is already connected or there's an error in getting the `authSig`, it returns `null`.
+
+#### Description:
+This function first checks if the wallet is already connected. If it's not, it attempts to retrieve the `authSig` from local storage. If successful, it connects to the wallet using the provided `pkpPubKey` and `rpcURL`. Once the wallet is successfully connected, it sends a success message and sets the `isWalletConnected` flag to `true`.
+
+### `signSession()`
+
+#### Returns:
+- The `authSig` from local storage if it exists, or `null` otherwise.
+
+#### Description:
+This function retrieves the `authSig` from local storage and returns it. If the `authSig` does not exist in local storage, an error message is sent, and the function returns `null`.
+