Optional check that ensure statement timeout is set on supported databases

[Łukasz Skarżyński]

See wemake-services/wemake-django-template#1064 for more details.

[Łukasz Skarżyński]

I've investigated this issue more deeply, so generally only 2 backends support setting to stop queries that execution take too long:

• postgresql via statement_timeout
• mysql via max_execution_time

When working on this feature we can think about adding some more checks for other database settings, because to implement this check we can reuse common components:

• new database backend's related class (something similar to django.db.backends.base.features) for getting settings names and values for particular thing (e.g timing out statements)
• some common validators of this settings (e.g. statement_timeout cannot be turned off or set to too big value)

so adding new checks should be relatively simple.

[Nikita Sobolev]

Thanks a lot for your thoughtful research!

I guess we can start with postgres / mysql and someday eventually come to more complex engines.