http api/service: map .js to application/json and use in http clients

This is to trick the CDN into caching responses

http-api/src/main/java/net/runelite/http/api/feed/FeedClient.java

@@ -42,7 +42,7 @@ public class FeedClient
 	public FeedResult lookupFeed() throws IOException
 	{
 		HttpUrl url = RuneLiteAPI.getApiBase().newBuilder()
-			.addPathSegment("feed")
+			.addPathSegment("feed.js")
 			.build();
 
 		logger.debug("Built URI: {}", url);

http-api/src/main/java/net/runelite/http/api/item/ItemClient.java

@@ -174,7 +174,7 @@ public class ItemClient
 	{
 		HttpUrl.Builder urlBuilder = RuneLiteAPI.getApiBase().newBuilder()
 			.addPathSegment("item")
-			.addPathSegment("prices");
+			.addPathSegment("prices.js");
 
 		HttpUrl url = urlBuilder.build();
 

http-api/src/main/java/net/runelite/http/api/worlds/WorldClient.java

@@ -44,7 +44,7 @@ public class WorldClient
 	public WorldResult lookupWorlds() throws IOException
 	{
 		HttpUrl url = RuneLiteAPI.getApiBase().newBuilder()
-			.addPathSegment("worlds")
+			.addPathSegment("worlds.js")
 			.build();
 
 		logger.debug("Built URI: {}", url);