Use SRDF to exclude collision pairs in robot models

[sea-bass]

As shown in this example, Pinocchio allows setting collision pair exclusions using SRDF files.

This PR changes the main models (UR5 and Panda) to use such files, and adds a little more detail in the docs.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
pyroboplan
__init__.py	0	0	100%
pyroboplan/core
__init__.py	0	0	100%
planning_context.py	8	8	0%	1, 4, 9, 13–15, 17–18
utils.py	85	2	97%	155–156
pyroboplan/ik
__init__.py	0	0	100%
differential_ik.py	87	14	83%	146–147, 156–157, 181, 187, 193, 196, 224, 227, 235–236, 241, 247
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	45	0	100%
two_dof.py	8	0	100%
utils.py	5	0	100%
pyroboplan/planning
__init__.py	0	0	100%
cartesian_planner.py	92	5	94%	115, 139, 143–144, 207
graph.py	130	4	96%	58, 103, 195, 261
graph_search.py	53	2	96%	57, 135
path_shortcutting.py	48	1	97%	121
prm.py	105	25	76%	107, 136, 198–201, 227–228, 234–235, 258–259, 261–262, 314–317, 320, 323, 331–333, 337–338
rrt.py	145	28	80%	139–140, 142–143, 163–164, 167, 175, 208–209, 237, 332, 377–379, 383–384, 388–391, 394, 397, 405–407, 410, 413
utils.py	47	1	97%	80
pyroboplan/trajectory
__init__.py	0	0	100%
polynomial.py	151	38	74%	148, 150–151, 153–155, 157–158, 161–184, 187, 190, 193, 202, 229, 298
trajectory_optimization.py	114	0	100%
trapezoidal_velocity.py	168	33	80%	283–284, 329, 331–335, 337–338, 341–359, 362–364, 373
pyroboplan/visualization
__init__.py	0	0	100%
meshcat_utils.py	21	13	38%	40–41, 43, 45, 57, 81–82, 109, 131–134, 136
TOTAL	1328	190	85%

Tests	Skipped	Failures	Errors	Time
89	0 💤	0 ❌	0 🔥	22.787s ⏱️

[eholum]

LGTM! Pinocchio is the GOAT.

[eholum]

Yeah this is better.

[eholum]

This looks right and I don't seem to get invalid poses in the example IK but I didn't take a close close look