Cache public site pages and Apply homepage

[Parbhat]

Cache for the public site and apply homepage can be invalidated from settings > cache in Wagtail admin. The cache will also be invalidated automatically when a wagtail page is edited/created. The cache will not work for logged in users. And WAGTAIL_CACHE should be set True in local.py settings while testing locally.

Also, remove the unused code which adds cache_control in urlpatterns.

Link issue #949 and PR #1158

[frjo]

What do you think of this solution?

This will cache each table row that contains a single submission. Need to test to get the correct cache tag but this is a good start I believe.

Would like to use ADV_CACHE_TIMEOUT here instead of hardcoded "3600". Can you help with that? Tried using context but did not get it to work.

[frjo]

@Parbhat I removed the Advanced cache template tag parts. Should be in another pr and when I started testing the performance impact was small.

[Parbhat]

@frjo The solution for caching table using cache template tag looks good. There are some UI issues in some pages like dashboard start showing checkboxes at the start of the row. These issues can be fixed. We can also use the normal cache template tag instead of advanced django-adv-cache-tag. While testing noticed switching between Django cache tag and django adv cache tag, we need to clear the cache. Creating a separate PR will be good.