Add trajectory generation and execution example script

[sea-bass]

This PR adds a script that uses the Panda model to generate, view, and execute a trajectory.

It has the option of using trapezoidal velocity or polynomial profiles.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
pyroboplan
__init__.py	0	0	100%
pyroboplan/core
__init__.py	0	0	100%
planning_scene.py	5	5	0%	1, 3, 7–9
utils.py	53	8	84%	148–153, 155–156
pyroboplan/ik
__init__.py	0	0	100%
differential_ik.py	92	16	82%	127–128, 137–138, 162, 166–168, 174, 177, 205, 208, 216–217, 222, 228
nullspace_components.py	16	16	0%	3, 6, 22, 25, 45–46, 48–54, 57, 75–76
pyroboplan/models
__init__.py	0	0	100%
panda.py	40	0	100%
utils.py	4	0	100%
pyroboplan/planning
__init__.py	0	0	100%
graph.py	40	0	100%
rrt.py	165	25	84%	116–117, 119–120, 136–137, 145, 305, 350–355, 359–360, 364–366, 369–370, 378–379, 382–383
utils.py	6	0	100%
pyroboplan/trajectory
__init__.py	0	0	100%
polynomial.py	126	18	85%	127, 129–130, 132–134, 136–137, 140–143, 146, 151, 156, 165, 192, 261
trapezoidal_velocity.py	149	16	89%	313, 315–319, 321–322, 325–328, 331, 336, 341, 350
pyroboplan/visualization
__init__.py	0	0	100%
meshcat_utils.py	18	11	38%	40–41, 43, 45, 57, 81–82, 109–111, 113
TOTAL	714	115	83%

Tests	Skipped	Failures	Errors	Time
50	0 💤	0 ❌	0 🔥	12.643s ⏱️