Added ROS2-like Rust Examples

[imstevenpmwork]

This adds ROS2-like examples written in Rust for:

• Topics listener
• Topics talker
• Services client
• Actions client

Plus slight modifications to the Python ones. Mostly related to directory structure and logs.

Resolves #70
Main PR: #80

[eclipse-zenoh-bot]

@imstevenpmwork If this pull request contains a bugfix or a new feature, then please consider using Closes #ISSUE-NUMBER syntax to link it to an issue.

[eclipse-zenoh-bot]

@imstevenpmwork If this pull request contains a bugfix or a new feature, then please consider using Closes #ISSUE-NUMBER syntax to link it to an issue.

[imstevenpmwork]

@JEnoch I tested these in my vm. Could you review these before I move to the CPP ones 😄 ?

[JEnoch]

The examples are working fine 👍

Please address my review comments and complete the README.md similarly to Python's one (adding build instructions)

Question: why did you move the Python scripts into a src subdirectory ?
There is no need for this, and the zenoh-python examples are not in a src subdirectory.

[imstevenpmwork]

Thanks for the feedback!
Honestly moving the python scripts to the src folder was just preference. I did it to keep it consistent with the rest of the examples which will all have a src directory, also to give more visibility to the readme. But I can roll this back if you think it is not worth it, let me know :)

[imstevenpmwork]

@JEnoch Anything missing in this PR to merge the rust examples into the examples branch?