integration tests: add --force-color & set in CI

github actions supports color output, but does not report as a tty.
See https://github.com/actions/runner/issues/241.

test/mavsdk_tests/integration_test_runner/logger_helper.py

@@ -4,6 +4,7 @@ import os
 from enum import Enum
 from functools import lru_cache
 
+force_color = False
 
 class color(Enum):
     PURPLE = '\033[95m'
@@ -20,7 +21,7 @@ class color(Enum):
 
 
 def colorize(text: str, c: color) -> str:
-    if _supports_color():
+    if force_color or _supports_color():
         return str(c.value) + text + color.RESET.value
     else:
         return text