Motivation

We need to complete our parity push on supporting the LanguageExtensions transform.

Changes

• Model the foreach construct so that we get past the modelling phase. We treat this like we treat the Fn::Transform constructs, however to pass the tests we only support them in the resources position
• Override visit_node_object in the validator to ensure we don't ignore values that evaluate to None
• Move the setting of the change set update model earlier in the _setup_change_set_model as it's needed in the validator
• Unskip remaining language extensions tests (5)
  • add an additional field skip in test_transform_foreach_use_case because we now log useful information about unsupported resources in community (AppSync resources)

Next steps

• Support the Fn::Foreach:: construct at other template positions