Add param in physics system to enforce fixed constraint #115

Job	Run time
test / matrix-prep-bazelversion	5s
test / matrix-prep-os	4s
test / test (ubuntu-latest, 8.0.0, ., true)	51m 16s
test / test (ubuntu-latest, 7.3.1, ., true)	51m 43s
	1h 43m 8s

Provide feedback