implement Serialize/Deserialize for SystemTime with RFC3339 format

[kevinmingtarja]

Problem

We have two places that use a helper (ser_rfc3339_millis) to get serde to stringify SystemTimes into the desired format.

Summary of changes

Created a new module utils::serde_system_time and inside it a wrapper type SystemTime for std::time::SystemTime that serializes/deserializes to the RFC3339 format.

This new type is then used in the two places that were previously using the helper for serialization, thereby eliminating the need to decorate structs.

Closes #7151.

[jcsp]

Thanks Kevin - @VladLazar could you review please?

[VladLazar]

Thanks for the PR. Looks good to me (just one minor nit).

[github-actions]

2754 tests run: 2630 passed, 0 failed, 124 skipped (full report)

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Flaky tests (2)

Postgres 16

• test_multi_attach: debug

Postgres 15

• test_vm_bit_clear_on_heap_lock: debug

Code coverage* (full report)

• functions: 28.1% (6409 of 22846 functions)
• lines: 46.9% (45114 of 96245 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
36bb8dd at 2024-04-08T10:30:42.879Z :recycle:}

[VladLazar]

@kevinmingtarja looks like your PR raced with a change to the utilization endpoint. Could you please update your branch? I'll run CI again after that and merge it.

[kevinmingtarja]

@kevinmingtarja looks like your PR raced with a change to the utilization endpoint. Could you please update your branch? I'll run CI again after that and merge it.

Got it, I just updated my branch and resolved the merge conflict.

[VladLazar]

@kevinmingtarja thanks for the PR!