Tests: wakuext saved addressed

[churik]

• wakuext_upsertSavedAddress

  • Inserts or updates a saved address based on the provided saved address details.

• wakuext_deleteSavedAddress

  • Deletes a saved address using the specified address and a flag indicating if it's a test address.

• wakuext_getSavedAddresses

  • Retrieves a list of all saved addresses.

• wakuext_getSavedAddressesPerMode

  • Retrieves saved addresses based on the specified mode (testnet or mainnet).

• wakuext_remainingCapacityForSavedAddresses

  • Returns the number of saved addresses that can still be added, based on the specified mode (testnet or mainnet).