feat: qt5ct dark mode integration using ansible

[KhalilSelyan]

Description

This PR introduces an Ansible role named qt5ct_setup for configuring the qt5ct environment within the Autoware project. The role ensures qt5ct is installed, configures necessary settings in qt5ct.conf, updates QSS file paths, and manages the correct Autoware directory.
This functionality was moved from the PR in autoware_launch to ansible scripts

Related links

• Related Issue:
  • Enhancing Autoware Visualization with QT5CT for Unified and Improved Aesthetics #4534
• Related PR in autoware_launch:
  • feat: add an env variable to enable the new rviz2 theme autoware_launch#1017

Tests performed

• Tested the role to ensure it correctly identifies the Autoware directory containing the ansible folder.
• Confirmed that the qt5ct.conf file is correctly updated with the new stylesheet path without overwriting existing stylesheets.
• Ensured the QSS file paths are updated to absolute paths for icons.

Notes for reviewers

• The qt5ct_setup role dynamically finds the Autoware directory based on the presence of an ansible folder.
• The role includes tasks to comment out the QT_QPA_PLATFORMTHEME export line in /etc/X11/Xsession.d to avoid conflicts with other QT applications.

Interface changes

No changes to ROS topics or parameters.

Effects on system behavior

This PR affects the setup and configuration of the QT environment for Autoware by ensuring qt5ct is installed and configured with the appropriate settings. It should not affect runtime behavior but ensures a consistent UI experience for QT applications (specifically RViz) used within Autoware.

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[youtalk]

I think it's a very interesting approach. However, for existing RViz users, it would be a significant UI change. There is also a great need for documentation changes.
Therefore, why not limit this PR to just the dark mode toggle function and leave the shape changes of UI elements to another PR? This way, the size of the PR will be very small and it will be easier to review.