YAML Conformance Tests and Fixes

[stephenberry]

YAML Conformance + Writer Reliability

Summary

This PR brings the YAML implementation much closer to spec behavior by:

• adding full YAML conformance coverage from yaml-test-suite
• fixing parser behavior for many previously failing edge cases (anchors/aliases, indentation, tags/directives, block/flow interactions, scalar folding/chomping)
• expanding writer-focused tests, including large document generation and roundtrip checks for both glz::generic and C++ structs
• fixing YAML writer output in flow collections so multiline strings are emitted as valid double-quoted escaped scalars (instead of invalid block scalars inside {...} / [...])

Key Changes

• Added tests/yaml_conformance/yaml_conformance.cpp with broad conformance cases and integrated it into CTest.
• Updated YAML parsing logic in:
  • include/glaze/yaml/read.hpp
  • include/glaze/yaml/common.hpp
  • include/glaze/yaml/skip.hpp
• Updated writer behavior in:
  • include/glaze/yaml/write.hpp
• Expanded and hardened coverage in:
  • tests/yaml_test/yaml_test.cpp
  • including regression tests for flow-style multiline serialization and large writer documents.

Validation

• Conformance suite passes.
• yaml_test passes with new regression and large-document writer cases.

[packit-as-a-service]

One of the tests failed for f7a355a. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-i386/10100714-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3232397 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10100714/

[packit-as-a-service]

One of the tests failed for f7a355a. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-aarch64/10100714-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3232396 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10100714/

[packit-as-a-service]

One of the tests failed for f7a355a. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-x86_64/10100714-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3232394 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10100714/

[packit-as-a-service]

One of the tests failed for f7a355a. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-ppc64le/10100714-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3232395 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10100714/

[packit-as-a-service]

One of the tests failed for f7a355a. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-s390x/10100714-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3232393 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10100714/

[packit-as-a-service]

One of the tests failed for e7f2018. @admin check logs None, packit dashboard https://dashboard.packit.dev/jobs/copr/3233359 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10101069/

[packit-as-a-service]

One of the tests failed for aab7ec7. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-aarch64/10113200-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3245035 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10113200/

[packit-as-a-service]

One of the tests failed for 04ddecd. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-ppc64le/10113715-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3245841 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10113715/

[packit-as-a-service]

One of the tests failed for 1b3ad2e. @admin check logs None, packit dashboard https://dashboard.packit.dev/jobs/copr/3245846 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10113727/

[packit-as-a-service]

One of the tests failed for f824af3. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-aarch64/10116881-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3250909 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10116881/

[packit-as-a-service]

One of the tests failed for ae7dec6. @admin check logs None, packit dashboard https://dashboard.packit.dev/jobs/copr/3251007 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10116908/

[packit-as-a-service]

One of the tests failed for ae7dec6. @admin check logs None, packit dashboard https://dashboard.packit.dev/jobs/copr/3251006 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10116908/

[packit-as-a-service]

One of the tests failed for ae7dec6. @admin check logs None, packit dashboard https://dashboard.packit.dev/jobs/copr/3251008 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10116908/

[packit-as-a-service]

One of the tests failed for f824af3. @admin check logs https://download.copr.fedorainfracloud.org/results/packit/stephenberry-glaze-2305/fedora-rawhide-ppc64le/10116881-glaze/builder-live.log, packit dashboard https://dashboard.packit.dev/jobs/copr/3250910 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10116881/

[packit-as-a-service]

One of the tests failed for 2d8ed2f. @admin check logs None, packit dashboard https://dashboard.packit.dev/jobs/copr/3258499 and external service dashboard https://copr.fedorainfracloud.org/coprs/build/10125973/