* refactor: replace function call by var ref and move def near utilization in friendly and stylish formatters
* refactor: makes reduces visibility of Sarif.AddResult function by renaming it as addResult
* fix: stylish formatter doesn't handle singular/plural in the synthesis message
Some of the formatters were writing directly to stdout instead of returning the output. That made them more difficult to use them with revivelib. This PR updates those formatters to write to a buffer and return the resulting string.
