Refactored sim_color_detector and added tests

[pr05]

Description

This PR does the following:

• Refactors the simulation's color detection file into a node.
• Adds a test class for the rewritten node.

Fixes #742

Testing steps

Basic Functionality in Simulation

1. Run catkin_make
2. Run roslaunch igvc_gazebo qualification.launch
3. Launch RVIZ
4. Add raw and segmented camera images (from any camera image).

Expectation: The segmented image should match the raw image with the background being black and lines detailed in white.

Test Cases

1. Run catkin_make
2. Run catkin_make run_tests_igvc_platform_rostest_src_tests_test_test_sim_color_detector.test

Self Checklist

• [x] I have formatted my code using make format
• [x] I have tested that the new behavior works