Add lastSpokeAt property to Swift SDK

[brainwith]

This PR adds the lastSpokeAt property to the Swift SDK to align with Android and JS implementations.
It represents the last time a participant spoke, allowing consistent behavior across platforms.

[CLAassistant]

All committers have signed the CLA.

[pblazej]

Can we use Date? similarly to joinedAt I think this is consistent in other SDKs (Date in JS, Long? in Kotlin, DateTime in Flutter)

[brainwith]

Can we use Date? similarly to joinedAt I think this is consistent in other SDKs (Date in JS, Long? in Kotlin, DateTime in Flutter)

That’s a great suggestion — I can update it to use Date. The original use of Long was mainly for convenience when sorting on the caller side.

[pblazej]

LGTM, thank you for fixing that 🥇