cbuildbot: Move Buildbot printing functions to `cbuildbot_alerts` module

Move all of the cbuildbot-specific printing routines out of cros_logging
and in to a new submodule of cbuildbot. Fix up all usages of these
functions to point to the new location.

BUG=b:191490453
TEST=`run_tests`

Change-Id: I5f5f28256b89d2b0500c1c404e2718f33aceaa31
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2973409
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/wrapper3_unittest.py b/scripts/wrapper3_unittest.py
index 6237773..94edc15 100644
--- a/scripts/wrapper3_unittest.py
+++ b/scripts/wrapper3_unittest.py
@@ -40,7 +40,7 @@
     self.bindir.mkdir(parents=True)
     self.scripts_dir = self.chromite_dir / 'scripts'
     self.scripts_dir.mkdir()
-    for subdir in ('api', 'lib', 'third_party', 'utils'):
+    for subdir in ('api', 'cbuildbot', 'lib', 'third_party', 'utils'):
       (self.chromite_dir / subdir).symlink_to(
           Path(constants.CHROMITE_DIR) / subdir)
     for subfile in ('__init__.py', 'PRESUBMIT.cfg'):