Tar Remote Extensions

[awestover]

Add support for remote extensions. When requested, downloads a tar.gz file for the extension and then organizes the contained files. For instance, placing .so files in sharelib.

[github-actions]

1264 tests run: 1213 passed, 0 failed, 51 skipped (full report)

---

[awestover]

For local testing / testing on staging, the most relevant metric to look at is

state.metrics.load_libraries_ms = library_load_time;
"Loading shared_preload_libraries took {:?}ms", library_load_time

(because shared preload libraries are loaded during compute_start)

[awestover]

@cicdteam is working on improving the infra for this: https://github.com/neondatabase/aws/pull/405#issue-1804986517
EDIT: finished

[awestover]

Note: tests with real S3 are expected to fail right now because we haven't uploaded the necessary files to S3 yet.

[awestover]

TODO:

Merge postgres changes:

• Request extension files and libraries from compute_ctl v14 postgres#289.
• Request extension files and libraries from compute_ctl v15 postgres#290.

Control Plane changes:

• TODO: control access
• https://github.com/neondatabase/cloud/pull/5896

Upload files to S3 via Dockerfile.compute-node

• Zip Extensions #4667
  actually, WIP: Compress extensions for S3 #4753 seems better :)
  and Create ext_index.json #4764

Infra changes:

• create prod buckets

[cicdteam]

This need to solve to allow computes access to S3 buckets (extension storage)
https://github.com/neondatabase/cloud/issues/6025

[awestover]

it looks like the first round trip to AWS is really expensive even if it's downloading a really small file? like ~3KB
never mind, this was because I was in a different region from the bucket
on github it is more like ~50ms per was round trip

[awestover]

pretty sure the cloud test failures are unrelated

[awestover]

I left some comments about a couple potential changes. nothing major