Add wse_pantheon module for Pantheon integration

Rishi Kulshreshtharequested to merge
issue/wse-3544287:3544287-wse-pantheon into 3.0.x
  • Implement Pantheon-compatible cookie handling for workspace preview sessions
  • Add controller decorator to redirect preview requests to stored destinations
  • Add cookie workspace negotiator decorator for Pantheon preview cookies
  • Implement page cache policy to disallow caching of preview requests
  • Include comprehensive unit tests for all new components

Closes #3544287

Merge request reports