Support latest PXT with GC (#1798)

* Enable gc and basic compilation fixes

* Add missing GC stuff

* Set microbit-dal version

* Disable jacdac in servo

* UTF fixes

* TS build fixes

* Auto-generated files update

* We only seem to have that much

* Fix for new new compiler

* Account for uninitialized scheduler

* Intialize memory allocator

* bump references

* updated package

* Set image tag, requires https://github.com/Microsoft/pxt/pull/5262

* updated project summaries

* Fixing block tests

libs/servo/pxt.json

@@ -1,3 +1,13 @@
 {
-    "additionalFilePath": "../../node_modules/pxt-common-packages/libs/servo"
+    "additionalFilePath": "../../node_modules/pxt-common-packages/libs/servo",
+    "files": [
+        "README.md",
+        "servo.ts",
+        "ns.ts",
+        "targetoverrides.ts"
+    ],
+    "public": true,
+    "dependencies": {
+        "core": "file:../core"
+    }
 }