Add test for a union using an alias with scope

[richiware]

Description

Add tests for the regression type for issue #21823 in eProsima/Fast-DDS-Gen#411.

Depends on:

• [21824] Regression test for 21823 dds-types-test#39

@Mergifyio backport 3.1.x 3.0.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
• N/A 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)
• N/A Changes are backport compatible: they do NOT break ABI nor change library core behavior.
• N/A 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.

[MiguelCompany]

@Mergifyio backport 3.1.x 3.0.x

[mergify]

backport 3.1.x 3.0.x

❌ No backport have been created

• #5354 Add test for a union using an alias with scope (backport #5330) has been created for branch 3.1.x
• Backport to branch 3.0.x failed

Git reported the following error:

Auto-merging include/fastdds/dds/xtypes/type_representation/detail/dds_xtypes_typeobject.hpp
Auto-merging src/cpp/fastdds/builtin/type_lookup_service/detail/TypeLookupTypes.hpp
Auto-merging src/cpp/statistics/types/monitorservice_types.hpp
Auto-merging src/cpp/statistics/types/types.hpp
Auto-merging test/blackbox/types/core/core_types.hpp
Auto-merging test/blackbox/types/statistics/monitorservice_types.hpp
Auto-merging test/blackbox/types/statistics/types.hpp
Auto-merging test/dds-types-test/declarations.hpp
Auto-merging test/dds-types-test/external.hpp
Auto-merging test/dds-types-test/unions.hpp
CONFLICT (content): Merge conflict in test/dds-types-test/unions.hpp
Auto-merging test/dds-types-test/unionsCdrAux.hpp
CONFLICT (content): Merge conflict in test/dds-types-test/unionsCdrAux.hpp
Auto-merging test/dds-types-test/unionsCdrAux.ipp
CONFLICT (content): Merge conflict in test/dds-types-test/unionsCdrAux.ipp
Auto-merging test/dds-types-test/unionsPubSubTypes.cxx
CONFLICT (content): Merge conflict in test/dds-types-test/unionsPubSubTypes.cxx
Auto-merging test/dds-types-test/unionsPubSubTypes.hpp
CONFLICT (content): Merge conflict in test/dds-types-test/unionsPubSubTypes.hpp
Auto-merging test/dds-types-test/unionsTypeObjectSupport.cxx
CONFLICT (content): Merge conflict in test/dds-types-test/unionsTypeObjectSupport.cxx
Auto-merging test/dds-types-test/unionsTypeObjectSupport.hpp
CONFLICT (content): Merge conflict in test/dds-types-test/unionsTypeObjectSupport.hpp
Auto-merging test/dds/xtypes/TypeLookupServicePublisher.h
Auto-merging test/dds/xtypes/TypeLookupServiceSubscriber.h
Auto-merging test/dds/xtypes/TypesTestsCases/Cases_unions.json
Auto-merging test/feature/dynamic_types/dds_types_tests/DynamicTypesUnionsDDSTypesTests.cpp
CONFLICT (content): Merge conflict in test/feature/dynamic_types/dds_types_tests/DynamicTypesUnionsDDSTypesTests.cpp
Auto-merging test/unittest/dds/xtypes/serializers/idl/types/union_struct/gen/union_struct.hpp
Auto-merging test/unittest/dds/xtypes/serializers/json/types/comprehensive_type/gen/ComprehensiveType.hpp
Failed to merge submodule thirdparty/dds-types-test (not checked out)
CONFLICT (submodule): Merge conflict in thirdparty/dds-types-test
Recursive merging with submodules currently only supports trivial cases.
Please manually handle the merging of each conflicted submodule.
This can be accomplished with the following steps:
 - come back to superproject and run:

      git add thirdparty/dds-types-test

   to record the above merge or update
 - resolve any other conflicts in the superproject
 - commit the resulting index in the superproject
error: could not apply 5c5a7c0b1... Add test for a union using an alias with scope  (#5330)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".