Using Sonar Metadata in FOV/Pointcloud Scripts

[micat001]

Change Overview

Biggest change is adding the sonar_msg_metadata class to unify how we access metadata across the FOV and point cloud scripts.

Other changes:

• Vectorizing geometry creation
• Clarifying comments around sonar_thresholding
• Separate self.intensity_threshold from it's intended purpose and prevent it from being used in multiple places
• Moving geometry creation (point cloud) and vector list creation (fov) back into the class method, as I think they are specific to those classes and not specific to msg metadata
• Consistent naming between the two files (mostly sonar_msg_* for the callback and msg names)

Scaling Stuff

Here's a visualization of the first 1000 points of the sonar_msg and the different scaling methods.

The "clipped" line is what we are currently using:

PC Visualization

With no thresholding

With thresholding (only positive values)

With thresholding (only values > 0.1)

[lauralindzey]

Done with my review; looks fine. Feel free to merge whenever ... consider all of my comments optional.

Possibly the only thing worthy of discussion comes down to code style preferences: more FP-like or more OOP like. I'm a fan of being functional when possible =)