[19505] Process environment variables on XML

[MiguelCompany]

Description

This PR adds environment variables processing on the text values of XML.
This way the user could write something like the following:

# In bash terminal
export ROBOT_IP_ADDRESS=192.168.0.1

# In XML profile
<?xml version="1.0" encoding="UTF-8" ?>
<profiles xmlns="http://www.eprosima.com/XMLSchemas/fastRTPS_Profiles">
    <participant profile_name="env_var_parsing_example">
        <rtps>
            <builtin>
                <initialPeersList>
                    <locator>
                        <udpv4>
                            <address>${ROBOT_IP_ADDRESS}</address>
                        </udpv4>
                    </locator>
                </initialPeersList>
            </builtin>
        </rtps>
    </participant>
</profiles>

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.
• Changes are ABI compatible.
• Changes are API compatible.
• New feature has been added to the versions.md file (if applicable).
• New feature has been documented/Current behavior is correctly described in the documentation.
  Related documentation PR: [19583] Add documentation for environment variables expansion on XML Fast-DDS-docs#556
• N/A Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• Check contributor checklist is correct.
• Check CI results: changes do not issue any warning.
• Check CI results: failing tests are unrelated with the changes.

[MiguelCompany]

@richiprosima Please test this

[MiguelCompany]

@richiprosima Please test this

[MiguelCompany]

@richiprosima Please test mac.

[MiguelCompany]

@richiprosima Please test this

[MiguelCompany]

@richiprosima Please test this

[EduPonz]

LGTM with green CI

[EduPonz]

@richiprosima please test this