appsdk-bump-app-catalog 521 bumping sdk to 2039-b6f76bc

sdk commit: RallySoftware/appsdk@b74b3811f1f96b354b0d99728d9f2c55db5c4ecf
author: Robb Lee
message: S65704: updated the ModelFilter to load the models it needs based off of model names

sdk commit: RallySoftware/appsdk@e55c0572900af91796eb867bd9392153e9740ce8
author: Robb Lee
message: Revert "S65704: updated the ModelFilter to load the models it needs based off of model names"

sdk commit: RallySoftware/appsdk@b6f76bc51a6cb81767d23039c848bfab036edfcf
author: Robb Lee
message: Revert "S64847: TreeGrid refactored to not load models.  Added TreeStoreBuilder to simplfy store creation."