Fix Smooth CV Limit, Minimum UFE Version, and Sandbox updates

Description

Two significant changes were made here:

1. Added the CoAP route /session/cv_limit_smooth to change the cartesian velocity limit smoothly. See CoAP/Constants.cs and CoAP/RobotClient.cs. Side Note: I lost track of #254, which would have been appropriate to implement now. I will keep it on my radar for the near future.

2. The mainboard firmware version that I had identified as the minimum necessary for UFE features was incorrect, so that has been changed from 6.6.0 to 6.7.0 in CoAP/Constants.cs.

Most of the changes in this merge request are just supporting tweaks that I made to the example and sandbox programs HoldPosition, DisplayBasicInfo, ForceOutputTest, and SafetySystemsTest while debugging firmware. That includes the changes to Util/ConsoleManager.cs and Util/ClassExtensions/ValueExtensions.cs, and the addition of the file Math/Round.cs. These changes in Util are just about getting the console display to look right during those test programs.

Because I re-ordered ForceOutputTest and changed variable names to all be more consistent with the other BurtSharp programs, it looks like I touched every single line of that file. I would just recommend running the program and testing the different features provided by the keyboard presses.

What to focus on

• Test using mainboard firmware tagged mainboard-ramp-cv-limit, or dev-mainboard-6.8.0 once that is ready.
• Test with burt/games/burt-therapist-ui!415, burt/games/burt-follow-me!186, and burt/games/burt-strength-assessment!105 to and ensure that setting cartesian velocity limit and haptic vibrations still work the same, despite the new options being added. Also confirm that safety wall, handedness switching, and user grav comp bugs related to force discontinuities have all been resolved.