refactor: Move top level constants to it's own modules

src/invidious/helpers/helpers.cr

@@ -1,5 +1,7 @@
 require "./macros"
 
+TEST_IDS = {"AgbeGFYluEA", "BaW_jenozKc", "a9LDPn-MO4I", "ddFvjfvPnqk", "iqKdEhx-dD4"}
+
 struct Nonce
   include DB::Serializable
 

src/invidious/helpers/utils.cr

@@ -1,3 +1,5 @@
+PUBSUB_URL = URI.parse("https://pubsubhubbub.appspot.com")
+
 # See http://www.evanmiller.org/how-not-to-sort-by-average-rating.html
 def ci_lower_bound(pos, n)
   if n == 0