Conan migration

closes #58 #63

This MR accomplishes:

• Migration of comms-software to use etl as a conan package
• Use of the team's logger and ecss-services conan packages
• Handling of cross-platform and component-drivers

Note:

• The ccsds-services submodule is removed from CMake due to conflicts. It's not yet utilized in comms-software so temporarily removing it from the build is ok. Re-integrating it requires packaging it in a similar way as the ecss-services package.
• physical-layer is still handled as a submodule.