[bip9] Combine csv and segwit into one, as the enum establishes

src/versionbitsinfo.cpp

@@ -12,11 +12,7 @@ const struct VBDeploymentInfo VersionBitsDeploymentInfo[Consensus::MAX_VERSION_B
         /*.gbt_force =*/ true,
     },
     {
-        /*.name =*/ "csv",
-        /*.gbt_force =*/ true,
-    },
-    {
-        /*.name =*/ "segwit",
+        /*.name =*/ "csv-segwit",
         /*.gbt_force =*/ true,
     }
 };