if metadata file did not exist it would crash

[GitHK]

What do these changes do?

When requesting metadata for a file which dose not exist storage would be crashing. This is now avoided.

Note: without this fix deployed to staging and production the fixed jupyter-labs will not work.

Related issue/s

addresses part of ITISFoundation/osparc-issues#429

How to test

Checklist

[codecov]

Codecov Report

Merging #2201 (21bab22) into master (4772247) will increase coverage by 3.9%.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           master   #2201     +/-   ##
========================================
+ Coverage    73.0%   76.9%   +3.9%     
========================================
  Files         465     249    -216     
  Lines       17905   10381   -7524     
  Branches     1763    1026    -737     
========================================
- Hits        13082    7993   -5089     
+ Misses       4362    2064   -2298     
+ Partials      461     324    -137     

Flag	Coverage Δ
integrationtests	65.3% <ø> (+<0.1%)	⬆️
unittests	69.5% <ø> (+3.1%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
.../simcore-sdk/src/simcore_sdk/node_data/__init__.py	0.0% <0.0%> (-100.0%)	⬇️
...erver/src/simcore_service_webserver/rest_models.py	0.0% <0.0%> (-91.2%)	⬇️
...src/simcore_service_sidecar/celery_configurator.py	0.0% <0.0%> (-91.2%)	⬇️
...core-sdk/src/simcore_sdk/node_data/data_manager.py	0.0% <0.0%> (-89.8%)	⬇️
...src/simcore_service_webserver/activity/handlers.py	27.1% <0.0%> (-62.9%)	⬇️
...ver/src/simcore_service_webserver/rest_handlers.py	48.1% <0.0%> (-51.9%)	⬇️
...simcore_service_webserver/activity/module_setup.py	55.5% <0.0%> (-44.5%)	⬇️
.../simcore_service_webserver/security_permissions.py	0.0% <0.0%> (-43.8%)	⬇️
.../src/simcore_service_webserver/diagnostics_core.py	50.8% <0.0%> (-39.0%)	⬇️
...rc/simcore_service_webserver/catalog_api_models.py	55.5% <0.0%> (-33.4%)	⬇️
... and 263 more

[KZzizzle]

beauty in simplicity