- Remove the external strain map and add a ExternalStrains property array for the clustered particles
- ExternalStrain field now just add to the external strain property of the particle and let the clustering code process it once per physics step
- Remove the unecessary maps returned by BreakingModel
- Updated headless chaos
#rb brice.criswell, ori.cohen
#ROBOMERGE-AUTHOR: cedric.caillaud
#ROBOMERGE-SOURCE: CL 20488364 via CL 20488374 via CL 20488388
#ROBOMERGE-BOT: UE5 (Release-Engine-Staging -> Main) (v954-20466795)
[CL 20490189 by cedric caillaud in ue5-main branch]