Add Invidious comments support

Model/Applications/VideosApp.swift

@@ -51,10 +51,6 @@ enum VideosApp: String, CaseIterable {
         self == .piped
     }
 
-    var supportsComments: Bool {
-        self == .piped
-    }
-
     var searchUsesIndexedPages: Bool {
         self == .invidious
     }