♻️ Refactors webserver module director_v2 and breaks dependency cycles

[pcrespov]

What do these changes do?

This PR refactors web-server service to prepare for new features that will be introduce in a separate PR #2556

• ♻️ Splits director-v2 app module into submodules for
  • _settings: Defines BaseSettings-based settings with options to configure this module
  • _handlers: defines handlers registered in the aiohttp's app.router
  • _core: includes core functionality
  • _api: exposes functions to other app modules
• ♻️ Splits project app module's handler into smaller submodules
• 🐛 Replaces built-in TimeoutError by asyncio.TimeoutError. Those are differemt things.
• ♻️ Cleanup simcore_service_webserver.utils
• ♻️ Removed dependency cycles.

$ cat $HOME/.pydeps
[pydeps]
max_bacon = 3
no_show = True
verbose = 1
pylib = False
exclude =
    os
    re
    sys
    collections
    __future__
    aiohttp
    __main__
    celery
    attr
    yaml
$ pip install pydeps   
$ pydeps src/simcore_service_webserver --show-cycles

Related issue/s

• ⚗️ MetaModeling backlog #2392
  • Refactors directorv2 app-module to introduce PR ✨ Meta-modeling infrastructure: iterators #2556

How to test

Checklist

[codecov]

Codecov Report

Merging #2567 (df0bef2) into master (b0342a5) will increase coverage by 0.1%.
The diff coverage is 84.3%.

@@           Coverage Diff            @@
##           master   #2567     +/-   ##
========================================
+ Coverage    76.8%   77.0%   +0.1%     
========================================
  Files         623     618      -5     
  Lines       24050   24073     +23     
  Branches     2357    2347     -10     
========================================
+ Hits        18483   18537     +54     
+ Misses       4938    4907     -31     
  Partials      629     629             

Flag	Coverage Δ
integrationtests	65.6% <71.6%> (+0.1%)	⬆️
unittests	71.4% <82.6%> (+<0.1%)	⬆️

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

Impacted Files	Coverage Δ
...b/server/src/simcore_service_webserver/__init__.py	100.0% <ø> (ø)
...rc/simcore_service_webserver/application_config.py	93.0% <ø> (ø)
.../server/src/simcore_service_webserver/constants.py	100.0% <ø> (ø)
...s/web/server/src/simcore_service_webserver/meta.py	72.7% <ø> (+8.4%)	⬆️
...erver/src/simcore_service_webserver/storage_api.py	50.0% <50.0%> (+0.9%)	⬆️
...ce_webserver/resource_manager/garbage_collector.py	74.7% <60.0%> (+0.8%)	⬆️
.../src/simcore_service_webserver/director_v2_core.py	66.9% <66.9%> (ø)
...re_service_webserver/projects/projects_handlers.py	83.4% <87.5%> (+0.7%)	⬆️
...simcore_service_webserver/projects/projects_api.py	83.3% <90.9%> (ø)
...rvice_webserver/projects/projects_tags_handlers.py	92.5% <92.5%> (ø)
... and 36 more

[GitHK]

very nice.

[sanderegg]

ok... I'm a little bit scared of my next rebase ;)