remove INLINE_DECAP_IPIP from edge_*/fna_* flavors since GUE_ENCAP is default

Summary:
all edge_* flavors are using edge_defines and gue_define and all fna_* flavors are using fna_defines and gue_define. there is no
  need to have have INLINE_DECAP_IPIP defined in edge_defines and fna_defines. Removing it.
Created gue decap unit tests for all edge_/fna_ flavors.

I don't see how OSS code config those INLINE_DECAP macros. Maybe no change is needed there. Would confirm. https://github.com/facebookincubator/katran/blob/main/katran/lib/Makefile-bpf

Reviewed By: p-shah256

Differential Revision: D92073353

fbshipit-source-id: 4bf292aedd353662d74f64954ec18f61f3553c41

Author: Fei Chen

katran/lib/bpf/balancer_consts.h

@@ -383,12 +383,6 @@ v2 tracks misses for TCP non syns */
  * LOCAL_DELIVERY_OPTIMIZATION - allow to do optimization on local traffic,
  * where vip and real address are specified the same machine
  */
-#ifdef INLINE_DECAP
-#ifndef INLINE_DECAP_IPIP
-#define INLINE_DECAP_IPIP
-#endif // of INLINE_DECAP_IPIP
-#endif
-
 #ifdef INLINE_DECAP_IPIP
 #ifndef INLINE_DECAP_GENERIC
 #define INLINE_DECAP_GENERIC

katran/lib/testing/fixtures/KatranDecapStatsTestFixtures.h

@@ -59,7 +59,7 @@ extern "C" {
 namespace katran {
 namespace testing {
 
-const std::vector<PacketAttributes> DecapTestFixtures = {
+const std::vector<PacketAttributes> GUEDecapTestFixtures = {
   //1
   {
     .description = "GUE IPv6-in-IPv6 decap for IPv6 VIP fc00:1::1 port 80",