Sonar Overhaul

[Will-Denton]

Changes to the way sonar interprets data and makes the sonar faster overall

• Removed sonar-pub.py and incorperated everything into sonar.py
• Re-wrote all sonar methods so finding point of buoy is easier
• Re-made custom messages so no longer using old action files
• Added a constant sweep mode with image publishing
• More :)