Integrate screen APIs from common packages (#343)

* starting screen api intergration

* Further image integration

* Aligning with new screen apis

* Build fixes

* Adjust to common screen state

* Fix unpackPNG

* Add game library

* Optimize screen rendering

* bumping common packages

* updated shims

* moving images into ev3

* upgrading to common packages

* added try/use

* cap

* fixed tryp age

libs/game/pxt.json

@@ -0,0 +1,3 @@
+{
+    "additionalFilePath": "../../node_modules/pxt-common-packages/libs/game"
+}