Track log names in a json map AND Fix processing local log load as system

Update old style callbacks for chatFromLogFile functions to lambdas
Keep track of people's log's name using their IDs, but don't rename.
Fallback on ID if name is empty (if the grid is a meanie)
Also track group names this way, sometimes those change.
Prefer std::array, since we're in the area.

indra/llmessage/llcachename.h

@@ -57,6 +57,8 @@ public:
 	LLCacheName(LLMessageSystem* msg, const LLHost& upstream_host);
 	~LLCacheName();
 
+	const std::map<std::string, LLUUID>& getReverseMap() const;
+
 	// registers the upstream host
 	// for viewers, this is the currently connected simulator
 	// for simulators, this is the data server