refactor: Refactor status.py (#4864)

The one major functional change in this commit is around how we detect
running vs error states. Status reporting has a fundamental problem in
that we can't accurately tell if cloud-init is done because cloud-init
is actually several processes. There isn't always a way to tell whether
a service isn't running because it simply hasn't started yet vs the
service being blocked/crashed and will never start/finish.

In the past, if any of the cloud-init services reported an error, we
would assume that cloud-init as a whole has crashed and report that
cloud-init is "done", but with error. This commit flips that logic to
assume that cloud-init is always running unless we see indication that
cloud-init has completely finished. This means that
`cloud-init status --wait` may run forever if cloud-init has crashed or
is blocked on another service. This is preferable to returning early
and potentially allowing provisioning scripts that wait for cloud-init
to continue provisioning. On systemd-enabled systems, there is extra
logic to inspect the state of the services, so this should rarely be a
problem in practice.

Additionally, this commit includes the following refactoring:
- Split UXAppStatus into RunningStatus and ConditionStatus so they can
  be tracked independently
- Simplify the tabular printing
- On error print extended_status as "error - done" or "error - running"
- Add several helper functions in `get_status_details` to simplify
  logic
- Rename `_get_error_or_running_from_systemd` to `systemd_failed`
  and only return if error is detected
- Change "is running" logic to be determined solely by the existence
  of the status.json and results.json files.

cloudinit/cmd/cloud_id.py

@@ -9,7 +9,7 @@
 import sys
 
 from cloudinit.cmd.devel import read_cfg_paths
-from cloudinit.cmd.status import UXAppStatus, get_status_details
+from cloudinit.cmd.status import RunningStatus, get_status_details
 from cloudinit.sources import METADATA_UNKNOWN, canonical_cloud_id
 from cloudinit.util import error
 
@@ -66,11 +66,11 @@ def handle_args(name, args):
     @return: 0 on success, 1 on error, 2 on disabled, 3 on cloud-init not run.
     """
     status_details = get_status_details()
-    if status_details.status == UXAppStatus.DISABLED:
-        sys.stdout.write("{0}\n".format(status_details.status.value))
+    if status_details.running_status == RunningStatus.DISABLED:
+        sys.stdout.write("{0}\n".format(status_details.running_status.value))
         return 2
-    elif status_details.status == UXAppStatus.NOT_RUN:
-        sys.stdout.write("{0}\n".format(status_details.status.value))
+    elif status_details.running_status == RunningStatus.NOT_STARTED:
+        sys.stdout.write("{0}\n".format(status_details.running_status.value))
         return 3
 
     try: