new colors for importing missing issues infos as labels
import (non-duplicate) issues kinds and issues priorities as labels
fixed color not changing depending on function param
new function to extract issue fields that can be converted into "labels"
refactored JSON file loading into load_json() function
fetch issue's labels using new issue_label() function
removed duplicate console output on labels after refactoring of labels creation
fixed incorrect looping (one-depth too far) for printing milestones
cleanup: fixed typo, unused import, init config to None, line breaks