Suggested fix for issue #4273. The main change is in add_misformatted_file() to use the proper newline styles in each of the original/expected fields in each MismatchedBlock. The original code"s newline style is used for original while the config newline_style is used for expected.

The other changes are to add parameters to functions/structures to allow passing the config newline_style value to add_misformatted_file(). The new parameters required adding them to function calls in some of the emitter/json.rs test cases. In all these cases default values used.

Test new cases were added to emitter/json.rs, assuming there is no way to verify the json output using test cases files.

The approach taken is that add_misformatted_file() gets the proper newline strings and continues to add the newline to the end of the original/expected strings, using these values instead of constant \n. A simpler alternative may have been to continue adding \n to the end of the strings and then call apply_newline_style() to convert them to the proper newline style. However, that approach seem to be problematic from performance point of view, as the call is done separately for each original/expected field for each MismatchedBlock.

(This is probably the last new PR I am submitting in a while. I know it is a lot of effort and time to review and verify the changes, but I had the time and energy lately to try resolving some of the open issues. Still, if there are issues I can help resolving I will be happy to do that.)