[20650] Create InitialConnection for TCP initial peers 2.13 & 2.10 & 2.6 (backport #4947)

[mergify]

Description

This PR uses the features introduced in #4584 to ALWAYS create a connection channel for the TCP when initial peers are configured.

@Mergifyio backport 2.10.x 2.6.x

Contributor Checklist

• Commit messages follow the project guidelines.

• The code follows the style guidelines of this project.

• N/A 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)

• 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 #4947 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of a0a4fee has failed:

On branch mergify/bp/2.6.x/pr-4947
Your branch is up to date with 'origin/2.6.x'.

You are currently cherry-picking commit a0a4feeff.
  (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:
	modified:   src/cpp/rtps/builtin/discovery/participant/PDPSimple.cpp

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   test/blackbox/common/BlackboxTestsTransportTCP.cpp

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

[Mario-DL]

LGTM, failed tests unrelated