Implement more tests for trajectory forwarding

[fmauch]

Feature summary

Currently, we have one test testing trajectory forwarding. This sends a trajectory for execution that is using the driver's default forwarding method which is spline interpolation. This has been fixed in #721 which revealed a couple of options we should also test for:

• Use the movej-based trajectory execution
• Use a quintic spline for trajectory execution
• Check that sending in a position-only spline interpolation will fail