Kill when we have degenerate thruster setup

[David Santiago Soto]

TLDR: We should kill the sub when losing second thruster leaves us with a singular B-matrix.

Right now we only kill if we lose a third thruster, only giving warnings when the first two are lost. However this is not always safe as there are multiple ways of losing a second thruster that leave us without full state control.

This should be easy to check: (code should live in thruster mapper)

• Compose the B-matrix out of the thrusters left
• Check the determinant of the matrix is non-zero
• If it is zero, raise the thruster-kill alarm

This will help us avoid problems like what happened on May 14 which waste a lot of time and are potentially dangerous for the sub.