Consolidate Training and Resources Sections

[sunnydean]

Combine the following into a single Training Hub page:

• Tutorials and Learning Pathways
• EarthCODE and Recommended Materials
• Videos and Webinars
• Gallery
  Include clear links and a note that platform training can be requested through NoR. Update webinar links, including playlist on YouTube: https://www.youtube.com/@eoopenscience4372/playlists

[u3ks]

changes from pr #126