Add a "whoAmI" section in Origin/Cache's webUI

[h2zh]

Pelican Service:

• Client
• Plugin
• Registry
• Director
• Origin
• Cache
• Other (please give the detail)

Describe the solution you'd like
Origin/Cache admin should know what is the name their server is advertising with on their own dashboard (instead of checking it in Director/Registry).

Consume the API endpoint: fcedb26