Porting automated tasks and test cases into thin-edge.io repository

[gligorisaev]

Proposed changes

Robot Framework automated task and test cases have been stored in an private repository as POC, with this PR they will be ported to the main branch of the project.

Types of changes

• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• [ ] Documentation Update (if none of the other choices apply)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

Checklist

• [x] I have read the CONTRIBUTING doc
• [x] I have signed the CLA (in all commits with git commit -s)
• [ ] I ran cargo fmt as mentioned in CODING_GUIDELINES
• [ ] I used cargo clippy as mentioned in CODING_GUIDELINES
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have added necessary documentation (if appropriate)

Further comments

Automated task added:

• build_install_thinedge.robot

Automated test cases added:

• child_alarms
  • c8y_child_alarms_rpi.robot
• config_management
  • inotify_crate.robot
• customizing
  • log_path_config.robot
• MQTT_health_check
  • health_c8y-configuration-plugin.robot
  • health_c8y-log-plugin.robot
  • health_tedge_mapper_c8y.robot
  • health_tedge-agent.robot
  • health_tedge-mapper-az.robot
  • health_tedge-mapper-collectd.robot
• plugin_apt
  • improve_tedge_apt_plugin_error_messages.robot