chore: Use datetime.timedelta for defining durations in config

[john-bodley]

SUMMARY

Encoding time durations (timeout, wait, etc.) as int seems un-Pythonic in world of typing. Furthermore:

• It is not apparent whether a duration is in seconds, milliseconds, etc.
• There are inconsistencies in how these config variables are defined, e.g. we have SQLLAB_VALIDATION_TIMEOUT and SQLLAB_ASYNC_TIME_LIMIT_SEC, where the later encodes the temporal units in the name.

Using datetime.timedelta remedies both these problems, i.e., timedelta(hours=1). This PR merely seeds this mindset (in the context of the configs) by replacing constructs like,

SCREENSHOT_LOAD_WAIT = 60

with

SCREENSHOT_LOAD_WAIT = int(timedelta(minutes=1).total_seconds())

whereas in the future it should simply be

SCREENSHOT_LOAD_WAIT: timedelta = timedelta(minutes=1)

where the code is updated to expect a datetime.timedelta object.

Note I raised pallets-eco/flask-caching#266 to see whether Flask-Caching would consider adding native support for using a datetime.timedelta object which would further simplify the code if we adopted this pattern.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

CI.

ADDITIONAL INFORMATION

• Has associated issue:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #16029 (7ac7abd) into master (31d79ff) will decrease coverage by 0.20%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master   #16029      +/-   ##
==========================================
- Coverage   77.01%   76.81%   -0.21%     
==========================================
  Files         990      990              
  Lines       52517    52547      +30     
  Branches     6642     6642              
==========================================
- Hits        40448    40362      -86     
- Misses      11845    11961     +116     
  Partials      224      224              

Flag	Coverage Δ
hive	?
mysql	81.64% <100.00%> (+0.02%)	⬆️
postgres	81.64% <100.00%> (+<0.01%)	⬆️
presto	?
python	81.75% <100.00%> (-0.41%)	⬇️
sqlite	81.30% <100.00%> (+0.02%)	⬆️

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

Impacted Files	Coverage Δ
superset/config.py	91.24% <100.00%> (ø)
superset/db_engines/hive.py	0.00% <0.00%> (-82.15%)	⬇️
superset/db_engine_specs/hive.py	69.80% <0.00%> (-16.87%)	⬇️
superset/db_engine_specs/presto.py	83.47% <0.00%> (-6.91%)	⬇️
superset/views/database/mixins.py	81.03% <0.00%> (-1.73%)	⬇️
superset/connectors/sqla/models.py	88.00% <0.00%> (-1.70%)	⬇️
superset/db_engine_specs/base.py	87.98% <0.00%> (-0.39%)	⬇️
superset/models/core.py	89.61% <0.00%> (-0.26%)	⬇️
superset/utils/core.py	88.17% <0.00%> (-0.13%)	⬇️
superset/reports/api.py	91.30% <0.00%> (+3.51%)	⬆️

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[betodealmeida]

This is great, thanks @john-bodley !