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/core/control.cpp

@@ -318,6 +318,6 @@ namespace control {
     //%
     void __log(String text) {
         if (NULL == text) return;
-        pxt::sendSerial(text->data, text->length);
+        pxt::sendSerial(text->getUTF8Data(), text->getUTF8Size());
     }
 }