Enable/disable additions for @buy/pay restrictions + show a blocked notification whenever the floater would have opened to inform the user

Add @buy and @pay restrictions to block object purchases and avatar payments respectively (because of baguettes)

  -> Also prefer using isExiting() over isQuitting()

[FIXED] Assertion failure on m_Object.empty() in RlvHandler::cleanup() when an object only issues unknown commands
  -> In this case @nohax=n by an OpenCollar

to reflect previous commit and use correct pool size

following promotion of DRTVWR-476

This reverts commit bf999f2f due to revert of updater, this will be moved to separate 'epic' instead

This fails at teamcity due to missing LLTrans, but builds locally without issues. Reverting to not hold D501

This reverts commit 31d9930a.

Nat's suggested improvement to LLThreadSafeQueue that takes account of queue being empty as well as the status flag condition