WIP: errors middleware captures CancelledError in handlers

[pcrespov]

What do these changes do?

Related issue/s

Zero downtime: Connected users should be able to continue working with osparc when osparc micro-services are restarted #2212

How to test

Checklist

[codecov]

Codecov Report

Merging #2215 (8943673) into master (ab717cb) will decrease coverage by 0.0%.
The diff coverage is 44.4%.

@@           Coverage Diff            @@
##           master   #2215     +/-   ##
========================================
- Coverage    73.2%   73.2%   -0.1%     
========================================
  Files         465     465             
  Lines       17939   17946      +7     
  Branches     1766    1767      +1     
========================================
+ Hits        13145   13147      +2     
- Misses       4341    4346      +5     
  Partials      453     453             

Flag	Coverage Δ
integrationtests	65.5% <ø> (-0.1%)	⬇️
unittests	66.7% <44.4%> (-0.1%)	⬇️

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

Impacted Files	Coverage Δ
...service-library/src/servicelib/rest_middlewares.py	61.7% <44.4%> (-2.5%)	⬇️
...webserver/computation_comp_tasks_listening_task.py	88.1% <0.0%> (-3.3%)	⬇️
...erver/src/simcore_service_webserver/director_v2.py	87.2% <0.0%> (-0.9%)	⬇️
...simcore_service_webserver/projects/projects_api.py	88.4% <0.0%> (-0.6%)	⬇️
.../director/src/simcore_service_director/producer.py	60.4% <0.0%> (-0.3%)	⬇️
...ce_webserver/resource_manager/garbage_collector.py	77.6% <0.0%> (+2.7%)	⬆️

[pcrespov]

discarded