Add ktxreader and viewer libs to CocoaPods (#5573)

ios/CocoaPods/Filament.podspec

@@ -54,9 +54,11 @@ Pod::Spec.new do |spec|
     ss.vendored_libraries =
       "lib/universal/libgltfio_core.a",
       "lib/universal/libdracodec.a",
-      "lib/universal/libgltfio_resources.a"
+      "lib/universal/libgltfio_resources.a",
+      "lib/universal/libstb.a"
     ss.header_dir = "gltfio"
     ss.dependency "Filament/filament"
+    ss.dependency "Filament/ktxreader"
   end
 
   spec.subspec "camutils" do |ss|
@@ -98,4 +100,24 @@ Pod::Spec.new do |spec|
     ss.source_files = "include/math/*.h"
     ss.header_dir = "math"
   end
+
+  spec.subspec "ktxreader" do |ss|
+    ss.source_files = "include/ktxreader/*.h"
+    ss.header_mappings_dir = "include"
+    ss.vendored_libraries =
+        "lib/universal/libktxreader.a",
+        "lib/universal/libbasis_transcoder.a"
+    ss.dependency "Filament/image"
+    ss.dependency "Filament/filament"
+  end
+
+  spec.subspec "viewer" do |ss|
+    ss.source_files = "include/viewer/*.h"
+    ss.header_mappings_dir = "include"
+    ss.vendored_libraries =
+        "lib/universal/libviewer.a",
+        "lib/universal/libcivetweb.a"
+    ss.dependency "Filament/filament"
+    ss.dependency "Filament/gltfio_core"
+  end
 end