perf(entities): preloads owners when drawing lists of entities/likes

When drawing lists of entities/likes with a variety of owners, many owners
end up being loaded one by one (inefficient). This adds a component that
walks the list and preloads all the owners into the cache in one shot.

Fixes #5949
Merge pull request #6975 from mrclay/5949_2

perf(entities): preloads owners when drawing lists of entities/likes
feature(filestore): add a hook to fix detected mimetype

Moves mimetype detection logic for Microsoft zipped formats from a file
plugin into a core plugin hook.
Adds missing reference to mime_type,file hook in the list of
available hooks.
Adds information about available hooks for filtering mime and simple types
to upgrading instructions. Informs plugin devs that Microsoft
zipped format detection snippet can be removed from file upload actions.