Add support for detecting tasks in a "paused" state

[atc0005]

Ran into a situation where connections to the host (self-referencing) were refused and the affected task went into a "paused" state. Looking at the specific task I see the option to "Resume" the task.

E.g.,

Error text:

Failed to open TCP connection to rsat.example.com:443 (Connection refused - connect(2) for "rsat.example.com" port 443)

Ideally support would be available to detect tasks stuck in this state and surface them.

Even with these stuck tasks, scheduled sync plans continue to "run" therefore not triggering the existing check_rsat_sync_plans "there is a problem" logic.

Future note to self

check-rsat/internal/rsat/syncplans.go

Lines 183 to 210 in b08f17f

	// IsStuck indicates whether (after any applied grace time) the sync plan is
	// considered to be in a "stuck" state (Next Sync state set to past date/time).
	//
	// Grace time is applied to help prevent flagging a sync plan that is
	// "spinning up" or in a temporary pending status (e.g., on a busy system) as
	// problematic.
	//
	// NOTE: Very busy systems keeping sync plans in a pending state for an
	// extended duration are still likely to be flagged as non-OK by current
	// logic.
	func (sp SyncPlan) IsStuck() bool {
	now := time.Now().UTC()
	nextSync := time.Time(sp.NextSync).UTC()
	switch {
	case sp.Enabled && nextSync.Before(now):
	diff := now.Sub(nextSync).Minutes()
	if diff <= syncTimeGraceMinutes {
	return false
	}
	return true
	default:
	return false
	}
	}

[atc0005]

https://rsat.example.com/foreman_tasks/api/tasks?search=state=paused

Example "pretty" payload:

{
  "total": 657825,
  "subtotal": 0,
  "page": 1,
  "per_page": 20,
  "sort": {
    "by": "started_at",
    "order": "DESC"
  },
  "results": []
}

The bit that we're specifically focused on:

"subtotal": 0,