Revert "[ Observatory ] Add basic records support to Observatory"

This reverts commit fca7813650e18845cd4d5e7f4a57cf40c4a48d7e.

Reason for revert: Broke analyzer tryjob

Original change's description:
> [ Observatory ] Add basic records support to Observatory
>
> Fixes https://github.com/dart-lang/sdk/issues/50405
>
> TEST=Manual testing
>
> Change-Id: If14f434792c89e3509895fcdd17561df810798e3
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/268581
> Commit-Queue: Ben Konyi <bkonyi@google.com>
> Reviewed-by: Derek Xu <derekx@google.com>

TBR=bkonyi@google.com,rmacnak@google.com,derekx@google.com,dart-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I30c4404adb9ac8f1851a89a0c846cb70461e410c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/269220
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Auto-Submit: Derek Xu <derekx@google.com>
Reviewed-by: Devon Carew <devoncarew@google.com>