[23881] Avoid casting GUID_t into InstanceHandle_t

[MiguelCompany]

Description

During my investigation of the failing tests in #6070, I discovered we are wrongly casting a GUID_t into an InstanceHandle_t.

This PR fixes it in an ABI-compatible way by adding a new field to DomainParticipantImpl.

For 3.5.0, I will open another PR changing the API to return the InstanceHandle_t by value.

@Mergifyio backport 3.3.x 3.2.x 2.14.x

Contributor Checklist

• Commit messages follow the project guidelines.
• The code follows the style guidelines of this project.
• Tests that thoroughly check the new feature have been added/Regression tests checking the bug and its fix have been added; the added tests pass locally
• Any new/modified methods have been properly documented using Doxygen.
• N/A: Any new configuration API has an equivalent XML API (with the corresponding XSD extension)
• Changes are backport compatible: they do NOT break ABI nor change library core behavior.
• Changes are API compatible.
• N/A: New feature has been added to the versions.md file (if applicable).
• N/A: New feature has been documented/Current behavior is correctly described in the documentation.
• Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• The title and description correctly express the PR's purpose.
• Check contributor checklist is correct.
• If this is a critical bug fix, backports to the critical-only supported branches have been requested.
• Check CI results: changes do not issue any warning.
• Check CI results: failing tests are unrelated with the changes.

[mergify]

🧪 CI Insights

Here's what we observed from your CI run for c1c433a.

❌ Job Failures

Pipeline	Job	Health on master	Retries	🔍 CI Insights	📄 Logs
Fast DDS MacOS CI	mac-ci / fastdds_test ()		0	View	View
Fast DDS Windows CI	windows-ci / fastdds_test (RelWithDebInfo, examples), v142		0	View	View
	windows-ci / fastdds_test (RelWithDebInfo, examples), v143		0	View	View

[MiguelCompany]

@Mergifyio backport 3.3.x 3.2.x 2.14.x

[mergify]

backport 3.3.x 3.2.x 2.14.x

✅ Backports have been created

• #6155 [23881] Avoid casting GUID_t into InstanceHandle_t (backport #6148) has been created for branch 3.3.x
• #6156 [23881] Avoid casting GUID_t into InstanceHandle_t (backport #6148) has been created for branch 3.2.x
• #6157 [23881] Avoid casting GUID_t into InstanceHandle_t (backport #6148) has been created for branch 2.14.x