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

[FIXED] hasBehaviourExcept() with an empty option returns false even though a RLV_OPTION_MODIFIER active restriction exists
  -> RlvCommand::markRefCounted() is called from RlvBehaviourGenericProcessor<RLV_OPTION_MODIFIER> as expected
  -> However, the RlvCommand reference we pass throughout the entire command processing line is a reference to the originally parsed command and not a reference to the copy that was stored in the RlvObject's command list
  -> The fact that we're mutating a constant is excusable in this case since only the command processor will know whether an option command should end up getting reference counted
  -> This bug only applies to hasBehaviourExcept() since the behaviour reference counter was still incremented/decremented successfully and hasBehaviourExcept() does a deep check on the individual commands instead
  -> Fixes FIRE-24215

Add @versionnum:impl=<channel> as a way to get the RLV implementation version as <major><minor:02><patch:02><implementation id:02> (RLVa implementation id is 13)

  -> Perform an orderly shutdown and clear RLVa when wearables and the avatar objects are (mostly) still around

SL-12994 FIXED [Camera Presets] Zoom fraction should be saved as a part of Camera preset, not as separate setting

following promotion of DRTVWR-481