executors: improve admin page

Created by: LawnGnome

Plan of attack

• Remove RxJS and convert entirely to Apollo.
• Add polling.
• Add storybook.
• Improve empty state.
• Show and link to current jobs per executor.
• Expose more info:
  • Number of CPUs.
  • Memory.
  • CPU usage (graph?).
  • Memory usage (graph?).
• Ask design for input.

Eventually closes #27546.

Test plan

TBC; presumably some combination of storybook coverage and live testing.

App preview:

• Web

Check out the client app preview documentation to learn more.