Deprecate ConnTuple and related APIs.

Given IP-aware ConnKeys, ConnTuples aren't really required any more. ConnTuple
had two benefits:

- It preserved the original src/dst orientation from the packet headers it was
based on, which IPBasedConnKey now tracks and provides accessor methods for.

- In IPBasedAnalyzer::AnalyzePacket() its instance survived past the std:move()
of the key into NewConn(), which we sidestep by keeping the original src address
and port around until we need after the connection is obtained.

src/packet_analysis/protocol/udp/UDP.h

@@ -24,10 +24,7 @@ public:
     void Initialize() override;
 
 protected:
-    /**
-     * Parse the header from the packet into a ConnTuple object.
-     */
-    bool BuildConnTuple(size_t len, const uint8_t* data, Packet* packet, ConnTuple& tuple) override;
+    bool InitConnKey(size_t len, const uint8_t* data, Packet* packet, IPBasedConnKey& key) override;
 
     void DeliverPacket(Connection* c, double t, bool is_orig, int remaining, Packet* pkt) override;