Reintroduce C++ support and add usage tests for C++ (#4)

Reviewed-on: #4
Co-authored-by: Abdelrahman <said.abdelrahman89@gmail.com>
Co-committed-by: Abdelrahman <said.abdelrahman89@gmail.com>

codegen/array/snippets/stack_capacity_array_cpp

@@ -0,0 +1,4 @@
+([&]() {{ \
+  persistent {T} buf[CAPACITY] = {{}}; \
+  return {ArrayType}{{buf, 0, CAPACITY, sizeof({T})}}; \
+}}())