Database Access AWS discovery reliability milestone

[greedy52]

• [ ] Document (1 week)
  • [x] Revamp DB discovery guide
    • [x] https://github.com/gravitational/teleport/issues/41354
  • [x] Discovery IAM reference page (or in the same page)
  • [ ] (stretch) https://github.com/gravitational/teleport/issues/38924
  • [ ] (stretch) Document all common deployments (EC2, Helm, ECS)
• [ ] Clear some backlogs (1~3 weeks)
  • [x] https://github.com/gravitational/teleport/issues/38922
  • [ ] https://github.com/gravitational/teleport/issues/16188
  • [ ] https://github.com/gravitational/teleport/issues/43829
  • [ ] (stretch) https://github.com/gravitational/teleport/issues/31097
  • [x] https://github.com/gravitational/teleport/issues/29828
  • [ ] (stretch) https://github.com/gravitational/teleport/issues/38306
• [ ] Web Discovery Flow
  • [x] ECS deployment
    • [x] https://github.com/gravitational/teleport/issues/40787
    • [x] https://github.com/gravitational/teleport/issues/40174
    • [x] https://github.com/gravitational/teleport/issues/40522
    • [x] https://github.com/gravitational/teleport/issues/41255
    • [x] https://github.com/gravitational/teleport.e/issues/3603
  • [ ] (stretch) https://github.com/gravitational/teleport/issues/33477
  • [x] https://github.com/gravitational/teleport/issues/41256
  • [x] #41312