refactor: demos rewrite, rai_interfaces import guards

[maciejmajek]

Purpose

Using RAI as a standalone framework is unfeasible due to many custom ROS 2 dependencies. Some of the parts of RAI could already be used in a pip install rai installation.

Proposed Changes

This PR adds various changes including:

• Guarding the rai_interfaces, rai_openset ... imports
• Removing deprecated files
• Rewriting demos

Issues

Testing

• How was it tested, what were the results?

[boczekbartek]

@maciejmajek Could you please resolve confilicts?

[boczekbartek]

@maciejmajek
This PR introduces major changes. I left some initial questions about the plan support rai features.

[boczekbartek]

@maciejmajek I tried:

rm -rd build install log

import rai

and I have this output:

ModuleNotFoundError: No module named 'rai_interfaces'

I think the purpose of this PR is to have this error only in ros-dependent rai packages like demos, right?

[boczekbartek]

@maciejmajek

• rai_interfaces doesn't break rai import, warning is shown
• tested code for agriculture and rosbot demos: code doesn't throw errors, but doesn't work. Refactoring these demos will be tracked under issues: Refactor ROSBotXL demo to RAI 2.0 #477, Add ros2 service related tools to the agriculture demo #474
• turtlebot demo needs refactor: Refactor turtlebot demo to RAI 2.0 #476
• manipulation demo works 👍🏼

approving, and let's move forward with demos under issues