Feature/25 mvp integration

[vangeliq]

Main changes:

Picture Node:
Rewrote so this node attempts to open a folder and read the image files in the folder. This node now publishes the images as a ros2 image message called /input_image

Inference Node
Created an inference node that takes in the /input_image topic, and publishes the output image and bounding box of a yolo model. This node calls on a util class to do the preprocessing, inference and post processing.

Util Class
Added a utility class that uses the ultralytics API to do preprocessing, inference and post processing

Other changes

• updated README to include topic subscription/publishing behaviour of nodes. Added example arguments for the new nodes
• updated gitignore files to include .pt and some other folders
• edit setup file to accommodate including the util classes in the ROS2 nodes.