Ignore secret values in ChatThrottleLib hooks

[Nnoggie]

Summary

• Skip bandwidth accounting when chat hooks receive secret text or destinations.
• Avoid accessing chat values while aura secrets are active.
• Keep Classic and older clients working when secret APIs are unavailable.
• Bump ChatThrottleLib to version 32.

Why

ChatThrottleLib's secure hooks convert message text and destination to strings to estimate bandwidth. In restricted encounters, either value can be secret, and converting it raises an error. Ignoring those hook calls prevents the error without changing queued message delivery.

[Nevcairiel]

What exactly is the purpose of the ShouldAurasBeSecret call? All we care about is checking if the values are secret and thus strlen fails, nothing else.

[Nnoggie]

Yeah this was a copy paste leftover from a similar fix for another AddOn. Will slim down and check for the existence of issecretvalue as well.

[funkydude]

You'll need to add issecretvalue to the .luacheckrc file so this PR passes the checks.