Create blood loss feature

[MObrien-IDM]

Add blood loss feature to represent mL of blood lost per cycle. Those without HMB will average 30-40 mL per cycle; those with HMB will have over 80 mL per cycle.

At initialization, each agent is assigned "responsiveness" to HMB intervention, which is a scaling factor that will adjust the HMB intervention effectiveness up or down. Interventions should impact blood lost per cycle.