Warn for non saved plugins, fix #379

[JoranAngevaare]

What is the problem / what does the code in this PR do
Warn if targets are not saved. Otherwise people might get the wrong impression.

Can you give a minimal working example (or illustrate with a figure)?

st=straxen.contexts.xenonnt_online()
st.context_config['check_available'] = strax.to_str_tuple(list(st._plugin_class_registry.keys()))
st.select_runs()

Peaks-plugin is SaveWhen.NEVER. Therefore peaks is most likely not stored!
EventInfoDouble-plugin is SaveWhen.NEVER. Therefore event_info_double is most likely not stored!
nVETOPulseProcessing-plugin is SaveWhen.TARGET. Therefore records_nv is most likely not stored!
PeakPositionsNT-plugin is SaveWhen.NEVER. Therefore peak_positions is most likely not stored!
nVETORecorder-plugin is SaveWhen.TARGET. Therefore raw_records_coin_nv is most likely not stored!
nVETORecorder-plugin is SaveWhen.TARGET. Therefore lone_raw_records_nv is most likely not stored!
PeaksHighEnergy-plugin is SaveWhen.NEVER. Therefore peaks_he is most likely not stored!
nVETORecorder-plugin is SaveWhen.TARGET. Therefore lone_raw_record_statistics_nv is most likely not stored!
muVETOPulseProcessing-plugin is SaveWhen.TARGET. Therefore records_mv is most likely not stored!
AqmonHits-plugin is SaveWhen.TARGET. Therefore aqmon_hits is most likely not stored!
Fetching run info from MongoDB: 100%|██████████| 4881/4881 [00:05<00:00, 924.25it/s]

[JoranAngevaare]

@WenzDaniel , you think this makes sense?

[WenzDaniel]

Yes, I think it make sense. I do not know much about log.warnings. Is this warning just shown once when called st.select_runs ? I do not want to spam people.

[JoranAngevaare]

Only if you request for availability of a plugin that is not set by default. I here set it to all plugins:

st.context_config['check_available'] = strax.to_str_tuple(list(st._plugin_class_registry.keys()))

[WenzDaniel]

Okay perfect, looks fine. Thanks a lot.