Update logger

[JonathanWoollett-Light]

Changes

• Adds support for reconfiguring the logger at runtime. You can now call the logger API root multiple times without error.
• Greatly simplifies the logger implementation removing ~800 LoC.
• Reduces the size of the Firecracker stripped release binary by ~20kb (~0.7%) (2681136 -> 2664816).

Reason

See above.

License Acceptance

By submitting this pull request, I confirm that my contribution is made under
the terms of the Apache 2.0 license. For more information on following
Developer Certificate of Origin and signing off your commits, please check
CONTRIBUTING.md.

PR Checklist

• If a specific issue led to this PR, this PR closes the issue.
• The description of changes is clear and encompassing.
• Any required documentation changes (code and docs) are included in this PR.
• API changes follow the Runbook for Firecracker API changes.
• User-facing changes are mentioned in CHANGELOG.md.
• All added/changed functionality is tested.
• New TODOs link to an issue.
• Commits meet contribution quality standards.

---

• This functionality cannot be added in rust-vmm.

[codecov]

Codecov Report

Attention: 164 lines in your changes are missing coverage. Please review.

Comparison is base (b4871b1) 83.10% compared to head (f35250e) 82.97%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4047      +/-   ##
==========================================
- Coverage   83.10%   82.97%   -0.13%     
==========================================
  Files         225      223       -2     
  Lines       28605    28452     -153     
==========================================
- Hits        23772    23609     -163     
- Misses       4833     4843      +10     

Flag	Coverage Δ
4.14-c7g.metal	78.51% <33.87%> (-0.17%)	⬇️
4.14-m5d.metal	80.31% <34.27%> (-0.16%)	⬇️
4.14-m6a.metal	79.45% <33.87%> (-0.17%)	⬇️
4.14-m6g.metal	78.51% <33.87%> (-0.17%)	⬇️
4.14-m6i.metal	80.30% <33.87%> (-0.16%)	⬇️
5.10-c7g.metal	81.43% <33.87%> (-0.15%)	⬇️
5.10-m5d.metal	82.99% <34.27%> (-0.14%)	⬇️
5.10-m6a.metal	82.22% <33.87%> (-0.15%)	⬇️
5.10-m6g.metal	81.43% <33.87%> (-0.15%)	⬇️
5.10-m6i.metal	82.97% <33.87%> (-0.14%)	⬇️
6.1-c7g.metal	81.43% <33.87%> (-0.15%)	⬇️
6.1-m5d.metal	82.99% <34.27%> (-0.14%)	⬇️
6.1-m6a.metal	82.22% <33.87%> (-0.15%)	⬇️
6.1-m6g.metal	81.43% <33.87%> (-0.15%)	⬇️
6.1-m6i.metal	82.97% <33.87%> (-0.14%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/api_server/src/request/logger.rs	100.00% <100.00%> (ø)
src/jailer/src/env.rs	67.26% <100.00%> (-0.08%)	⬇️
src/vmm/src/arch/aarch64/cache_info.rs	96.41% <ø> (ø)
src/vmm/src/builder.rs	93.19% <ø> (ø)
...c/vmm/src/cpu_config/x86_64/cpuid/amd/normalize.rs	97.23% <ø> (ø)
...c/vmm/src/cpu_config/x86_64/custom_cpu_template.rs	100.00% <100.00%> (ø)
src/vmm/src/device_manager/mmio.rs	64.31% <ø> (ø)
src/vmm/src/devices/virtio/balloon/device.rs	88.34% <100.00%> (ø)
...rc/vmm/src/devices/virtio/balloon/event_handler.rs	72.72% <100.00%> (ø)
src/vmm/src/devices/virtio/balloon/util.rs	100.00% <100.00%> (ø)
... and 23 more

... and 4 files with indirect coverage changes

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