SL-10238: Viewer spport for push notifications from the simulator contaiting partial groups of settings.  Blend these settings into the current environment.

SL-10093: Client code to support experiences changing an environment.  Handle generic messages with "commands" to be executed.

Remove compilation and linkage of deferredUtil and indirect GLSL helper objects (current source of Intel ig4icd driver crash).

MAINT-7699: More robust cap protocol, better support for delete and support for individual tracks, support for setting environment by asset id in the cap
MAINT-7703: Initial flags sent in message protocol for parcels