WorkloadsReady=False covers different situations: a stopped VM has
no pod and its monitor reports it not operational on purpose, while a
disk whose DataVolume never populates is broken. A consumer that wants
to react to one and not the other had only the message text to go by.
The WorkloadMonitor status gains a Reason next to Message, set to
DataVolumeNotReady by the DataVolume check, and the Application API
carries it into the WorkloadsReady condition in place of the generic
reason whenever a monitor that is not operational names one.
Assisted-by: LLM
Signed-off-by: Aleksei Sviridkin <f@lex.la>