Is1570/study fails 500

[pcrespov]

What do these changes do?

Sometimes client with old cookies would get 500 error when access studies (see #1570). I noticed that the cache in the authentication would lead to situations in which the request would authorized a user that actually does not exists anymore (e.g. because the garbage collector has removed it)

• At the study access entrypoint:
  • Handles more safely "anonymous" users
  • Improves error handling
• deleting a user also clear auth cache

Related issue number

Fixes #1570

How to test

cd services/web/server
make install-dev
pytest tests/unit/with_dbs/test_access_to_studies.py

NOTE: this fix should go ASAP to production (when approved, can be cherrypicked in staging , tested and then released)

Checklist

• Did you change any service's API? Then make sure to bundle document and upgrade version (make openapi-specs, git commit ... and then make version-*)
• Unit tests for the changes exist
• Runs in the swarm
• Documentation reflects the changes

[codecov]

Codecov Report

Merging #1572 into master will increase coverage by 0.0%.
The diff coverage is 69.6%.

@@          Coverage Diff           @@
##           master   #1572   +/-   ##
======================================
  Coverage    72.4%   72.4%           
======================================
  Files         281     281           
  Lines       10737   10751   +14     
  Branches     1168    1168           
======================================
+ Hits         7783    7794   +11     
- Misses       2613    2617    +4     
+ Partials      341     340    -1     

Flag	Coverage Δ
#integrationtests	57.4% <35.4%> (-0.1%)	⬇️
#unittests	65.0% <69.6%> (+<0.1%)	⬆️

Impacted Files	Coverage Δ
...ce_webserver/resource_manager/garbage_collector.py	68.0% <0.0%> (ø)
.../web/server/src/simcore_service_webserver/utils.py	43.1% <33.3%> (-0.4%)	⬇️
packages/service-library/src/servicelib/utils.py	67.5% <50.0%> (ø)
...er/src/simcore_service_webserver/users_handlers.py	94.8% <50.0%> (ø)
...er/src/simcore_service_webserver/studies_access.py	87.8% <64.2%> (-0.5%)	⬇️
...rver/src/simcore_service_webserver/security_api.py	75.8% <100.0%> (+3.8%)	⬆️
.../server/src/simcore_service_webserver/users_api.py	94.3% <100.0%> (+0.1%)	⬆️

[GitHK]

I like the general improvements. Also like that you simulated the issue with a test case! We should do more of those.
Added some trivial suggestions.

[sanderegg]

some minor comments. great stuff.