Improve argument parsing in Actions

[azeey]

🦟 Bug fix

Summary

The RosGzBridge and GzServer now support different spellings for boolean arguments (True, true). This also simplifies how conditionals are used to create composable nodes by evaluating the conditionals and using them as regular Python booleans instead of relying on PythonExpression. It was actually the PythonExpression that was preventing support of boolean arguments spelled true/false.

This came up in #632
The launch file in XML can now use lower case boolean strings:
https://github.com/gazebosim/ros_gz/blob/25b6644b644183e09f517170ce41b5dc6f16d6b8/ros_gz_sim_demos/launch/air_pressure.launch.xml#L1C1-L15C10

The equivalent python launch file for just gzserver and the bridge would be:

from launch import LaunchDescription
from launch_ros.substitutions import FindPackageShare
from ros_gz_sim.actions import GzServer
from ros_gz_bridge.actions import RosGzBridge

def generate_launch_description():

    return LaunchDescription([
        GzServer(world_sdf_file='sensors.sdf', use_composition=True, create_own_container=True),
        RosGzBridge(bridge_name='bridge1', 
                    config_file=[FindPackageShare('ros_gz_sim_demos'), '/config/air_pressure.yaml'],
                    use_composition='true'
                    )
    ])

Note the use_composition argument can be a python boolean or a string (True or true). We should probably deprecate the string input at some point since that's not very Pythonic

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[ahcorde]

10:  - /opt/ros/rolling/bin/ament_flake8 --xunit-file /github/home/ws/build/ros_gz_bridge/test_results/ros_gz_bridge/flake8.xunit.xml
10:         # This is here to allow using strings or booleans as values for boolean variables when the Action is used from Python
10:                                                                                                    ^
10:         # Note that use_composition is set to a string while create_own_container is set to a boolean. The reverse would also work.
10:                                                                                                    ^
10:         # At some point, we might want to deprecate this and only allow setting booleans since that's
10:                                                                                                    ^
10:             self.__create_own_container = normalize_typed_substitution(TextSubstitution(text=create_own_container), bool)
10:                                                                                                    ^
10:             self.__use_composition = normalize_typed_substitution(TextSubstitution(text=use_composition), bool)
10:                                                                                                    ^
10:         kwargs:Dict = super().parse(entity, parser)[1]
10:               ^
10:         create_own_container_eval = perform_typed_substitution(context, self.__create_own_container, bool)
10:                                                                                                    ^
10: 1     E231 missing whitespace after ':'
10: 6     E501 line too long (125 > 99 characters)

[ahcorde]

https://github.com/Mergifyio backport jazzy

[mergify]

backport jazzy

✅ Backports have been created

• #665 Improve argument parsing in Actions (backport #663) has been created for branch jazzy but encountered conflicts