Importing DDS Cubemap with a resolution of 2048 takes 20 mins to import

Importing a DDS Cubemap with a resolution of 2048 takes approximately 20 mins to import into the engine. It will seemingly freeze the engine for the duration of the import.

Also reproduced in Promotable-CL-2469771

1. Open QAGame Editor
2. Import the Linked Cubemap Asset

RESULTS: Engine appears to freeze for approx. 20 mins. then finishes import of cubemap asset

EXPECTED: Engine should not be listed as Not Responding in Task Manager and it should not take 20 mins to import the texture

Editor freezes on .dds import

Importing DDS Cubemaps takes very, very long