Add encoding for the generated test-results file

[dakaa16]

Currently files read and written by Cobol Check are encoded based on encoding from the config.properties file. A write to the test result file could happen from different places in the code, based on a given format; ex.: It could be written by JaxB (lib for writing XML) and could be written by other dependencies in the future.

Encoding should be loaded into a writer (use services.filehelpers.EncodingIO). This writer should then be available to use by any service used to write to the file.

Current implementation without encoding can be found at features.launcher.ProcessOutputWriter.