Arm test

[jcorcoran]

Description

Added arm subsystem at request of Rick to support testing of mechanical assembly.

This is a hard copy of the waist subsystem that @gordonbchen made, but degrees converted to meters since this subsystem will be concerned with linear extensions vs rotations.

Type of change

• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Bugfix (non-breaking change which fixes an issue, add DEF # above in description)
• [ ] Environment change (changes to developer environment or CI configuration)
• [ ] Documentation Update (if none of the other choices apply)

How Has This Been Tested?

• Code builds
• Waist subsystem has previously been tested on surrogate hardware

Author Checklist:

• [x] I have performed a self-review of my code
• [x] I have added 1-2 reviewers
• [x] I have @mentioned relevant non-reviewers as an FYI
• [x] I have included a detailed description of my changes and their motivations

[amoscao]

Looks good, just need to fix some conflicts