[#6464] Added tests for GC tracker attachments and comments

Signed-off-by: Cory Johns <cjohns@slashdotmedia.com>
[#6464] Fixed issue with custom fields not persisting and added tests

Signed-off-by: Cory Johns <cjohns@slashdotmedia.com>
[#6464] Fixed test failing due to refactor

Signed-off-by: Cory Johns <cjohns@slashdotmedia.com>