fix(lifecycle): cleanup lifecycle

- removes unwieldy SkipUpdate return value in favor of errors.Is
- generalizes the code for all four phases
- allows timeout to be defined for all phases
- enables explicit unit in timeout label values (in addition to implicit minutes)

pkg/container/errors.go

@@ -6,3 +6,6 @@ var errorNoImageInfo = errors.New("no available image info")
 var errorNoContainerInfo = errors.New("no available container info")
 var errorInvalidConfig = errors.New("container configuration missing or invalid")
 var errorLabelNotFound = errors.New("label was not found in container")
+
+// ErrorLifecycleSkip is returned by a lifecycle hook when the exit code of the command indicated that it ought to be skipped
+var ErrorLifecycleSkip = errors.New("skipping container as the pre-update command returned exit code 75 (EX_TEMPFAIL)")