Fix new player-is-x mixins

- Call the real method from isFriended
- Call the real method from isIgnored
- Add null check for getClanMembers

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

runescape-api/src/main/java/net/runelite/rs/api/RSClient.java

@@ -338,4 +338,12 @@ public interface RSClient extends RSGameEngine, Client
 
 	@Import("destinationY")
 	int getDestinationY();
+
+	@Import("isFriended")
+	@Override
+	boolean isFriended(String name, boolean mustBeLoggedIn);
+
+	@Import("isIgnored")
+	@Override
+	boolean isIgnored(String name);
 }