feat: Propagate updated Media_Handler class across all WebberZone plugins

- Copy updated Media_Handler from contextual-related-posts-pro to all plugins
- Update namespace, prefix, constants, and option functions for each plugin
- Maintain plugin-specific configurations:
  - Better Search (Pro/Free): bsearch prefix, BETTER_SEARCH_DEFAULT_THUMBNAIL_URL
  - Where Did They Go From Here: wherego prefix, WHEREGO_PLUGIN_URL default
  - Knowledgebase (Pro/Free): wzkb prefix, WZKB_DEFAULT_THUMBNAIL_URL
  - Top 10 (Pro/Free): tptn prefix, TOP_TEN_DEFAULT_THUMBNAIL_URL
  - Contextual Related Posts: crp prefix, WZ_CRP_DEFAULT_THUMBNAIL_URL
- Preserve backward compatibility and functionality

Author: ajaydsouza