Tests - Update syntax and improve implementation

Update syntax, style, documentation and contracts for the testing suite.

Replace Assigment attempt with object test.
USe across loops instead of traditional loops.
Use a better implementation for converters.
I think it is missing the initial check ...

since it is a test classes I would do something like that  (but with better check assertion tag name)
if attached .... then
else
   check l_name_and_json_array_set: False end
end

This way, the test will catch those check violations