SH-4548 WIP Changes to avatar physics are propogated to observers

There was a broken linkage between the chest driver & driven parameters.
Fixed some cross-wearable flags to make sure the params are stored & linked
properly.

Will test to make sure params get properly transmitted next.

indra/newview/character/avatar_lad.xml

@@ -4371,7 +4371,7 @@
      group="1"
      sex="female"
      name="Breast_Physics_UpDown_Driven"
-     wearable="shape"
+     wearable="physics"
      edit_group="driven"
      value_default="0"
      value_min="-3"
@@ -4384,7 +4384,7 @@
      group="1"
      sex="female"
      name="Breast_Physics_InOut_Driven"
-     wearable="shape"
+     wearable="physics"
      edit_group="driven"
      value_default="0"
      value_min="-1.25"
@@ -4397,7 +4397,6 @@
      group="1"
      name="Belly_Physics_Torso_UpDown_Driven"
      wearable="physics"
-     cross_wearable="true"
      edit_group="driven"
      value_default="0"
      value_min="-1"
@@ -4410,7 +4409,6 @@
      group="1"
      name="Breast_Physics_LeftRight_Driven"
      wearable="physics"
-     cross_wearable="true"
      edit_group="driven"
      value_default="0"
      value_min="-2"