[20815] Only apply content filter to ALIVE changes (backport #4876)

[mergify]

Description

Backport of #4835 to 2.x

This PR fixes a bug that caused the content filter to also be applied to unregister and disposed samples. Since in those messages the only fields populated (if any) are the ones annotated with @key, the unregister and dispose samples did not pass the filter (in general) and thus were being discarded. This caused several issues:

1. When writing to more than 10 instances with default Qos (keep last 1, max_instances 10), only the first 10 samples were been received.
2. In best effort, when setting the history depth and max instances appropriately, all samples were received, but calls to unregister or dispose followed by a write were triggering sample_lost events, as the received sequence numbers were not consecutive (because of the filtering out of the unregister/dispose).

This PR fixes these issues by only querying for sample relevance when the CacheChange kind is ALIVE.

@Mergifyio backport 2.13.x 2.10.x 2.6.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.
• Check CI results: changes do not issue any warning.
• Check CI results: failing tests are unrelated with the changes.

---

This is an automatic backport of pull request #4876 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 9a64956 has failed:

On branch mergify/bp/2.6.x/pr-4876
Your branch is up to date with 'origin/2.6.x'.

You are currently cherry-picking commit 9a64956e2.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   include/fastrtps/types/DynamicLoanableSequence.hpp
	modified:   include/fastrtps/types/DynamicPubSubType.h
	modified:   src/cpp/CMakeLists.txt
	modified:   src/cpp/fastdds/publisher/filtering/ReaderFilterCollection.hpp
	new file:   src/cpp/rtps/reader/reader_utils.cpp
	new file:   src/cpp/rtps/reader/reader_utils.hpp
	modified:   test/blackbox/api/dds-pim/PubSubParticipant.hpp
	new file:   test/blackbox/api/dds-pim/PubSubTypeTraits.hpp
	modified:   test/blackbox/api/dds-pim/PubSubWriterReader.hpp
	modified:   test/blackbox/common/DDSBlackboxTestsContentFilter.cpp
	new file:   test/blackbox/types/dynamic_types_traits.hpp

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   src/cpp/rtps/reader/StatefulReader.cpp
	both modified:   src/cpp/rtps/reader/StatelessReader.cpp
	both modified:   test/blackbox/api/dds-pim/PubSubReader.hpp
	both modified:   test/blackbox/api/dds-pim/PubSubWriter.hpp
	both modified:   test/unittest/dds/publisher/CMakeLists.txt
	both modified:   test/unittest/statistics/dds/CMakeLists.txt

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[EduPonz]

Depends on:

• [20733] Fix support for @key annotation in Dynamic types (backport #4694) #4749

[EduPonz]

@richiprosima please test discovery-server

[EduPonz]

@richiprosima please test discovery-server