Calculate senderHash for Action messages

Calculate senderHash for Action messages

Fixes stylesheets not being able to reference sender hashes in Qss
selectors.

Allows the following to work:
ChatLine::nick#action[sender="00"]   { foreground: #e90d7f; }

Just like this currently works:
ChatLine::nick#plain[sender="00"] { foreground: #e90d7f; }