Medical - Better handle odd selection/hitpoint names

[PabstMirror]

Adds a backup method to get the correct selection if the model/uniform is weird.

fix #2768 - VR people have weird hitpoint selection names:

class HitHead: HitHead {
    name = "hitHead";

Seems to fix odd RHS uniforms (eg, this guy could not take damage from headshots):

bob = group player createUnit ["B_soldier_F", Position player, [], 0, "FORM"];
bob addUniform "rhs_uniform_cu_ucp";