* `context/target` tests must be in groups 1 - 2.
* `context/controller` tests must be in groups 3 - 5.
This makes it easier to efficiently organize groups and balance test runtimes.
function changed to do in place replacement, should be less expensive even with copy as it avoids 'sub copies', can compose with module_args_copy to create replacement for old behavior
attempt to fix#52910
* handle lists and subdicts correctly
* added missing exception case, which was not noticed since 'cleaning' was not working
* added comments to clarify exceptions
