refactor(core): move src/core to src/native

[BaptisteFoy]

This PR depends on #12063.

Rename src/core to src/native. This is laying ground as a following PR will need to import native code in ddtrace.__init__.py. Without this change this would create a dependency loop between ddtrace & ddtrace.core through event_hub.py.

This PR only renames files, so a non-regression test is the only thing needed.

Checklist

• PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[github-actions]

CODEOWNERS have been resolved as:

ddtrace/internal/native/__init__.py                                     @DataDog/apm-core-python
.github/workflows/rust-ci.yml                                           @DataDog/python-guild @DataDog/apm-core-python
ddtrace/internal/core/__init__.py                                       @DataDog/apm-core-python
ddtrace/internal/datastreams/processor.py                               @DataDog/apm-core-python
ddtrace/internal/processor/stats.py                                     @DataDog/apm-core-python
setup.py                                                                @DataDog/python-guild
tests/suitespec.yml                                                     @DataDog/python-guild @DataDog/apm-core-python
ddtrace/internal/native/_native.pyi                                     @DataDog/apm-core-python
src/native/Cargo.lock                                                   @DataDog/apm-core-python
src/native/Cargo.toml                                                   @DataDog/apm-core-python
src/native/ddsketch.rs                                                  @DataDog/apm-core-python
src/native/lib.rs                                                       @DataDog/apm-core-python

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: baptiste.foy/FA/core-to-native
Commit report: 7148c15
Test service: dd-trace-py

✅ 0 Failed, 208 Passed, 1390 Skipped, 5m 9.33s Total duration (35m 18.41s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-01-24 14:59:59

Comparing candidate commit 7148c15 in PR branch baptiste.foy/FA/core-to-native with baseline commit cf83444 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 394 metrics, 2 unstable metrics.