switch group-membership checks to IsInGroup / IsInRaid

ClassicAPI ships modern IsInGroup() / IsInRaid() backports — drop the
GetNumPartyMembers() > 0 and GetNumRaidMembers() > 0 idioms (and the
GetNumPartyMembers() > 0 or GetNumRaidMembers() > 0 conflation) for the
named-intent variants. UnitInRaid("player") → IsInRaid() at the same
sites.

modules/innervatecall.lua

@@ -39,11 +39,11 @@ pfUI:RegisterModule("innervatecall", function ()
       return "BATTLEGROUND"
     end
 
-    if GetNumRaidMembers() > 0 then
+    if IsInRaid() then
       return "RAID"
     end
 
-    if GetNumPartyMembers() > 0 then
+    if IsInGroup() then
       return "PARTY"
     end