Add pagination for admin interface

[provokateurin]

No description provided.

[provokateurin]

@susnux can you please pull all occurrences of the number of items per page into a constant so we can easily adjust it later instead of having to change 20 lines and potentially miss some.

[susnux]

@provokateurin done

[zak39]

Hi everyone,

I would like to share my feedback.

Currently, you are paginating the results related to the getAllFoldersWithSize function without passing a limit as a parameter to this function.

As a result, the query time to display 30 folders will be the same as that to display 3000 folders, in my opinion.

It might be beneficial to define both the offset and limit as parameters in the getAllFoldersWithSize  function, don’t you think? 🤔

[provokateurin]

@zak39 thanks for your feedback. I agree it would be much more efficient to let the DB handle the pagination, but the problem is that the controller method has some more logic to filter entries and I'm not sure if it is even possible or at least feasible to move all that into the query (which could also hurt performance a lot).

The reason we are adding this is that the frontend is not capable handling so many Team folders at once. I originally suggested that we might do pagination frontend-only, as the backend size and network requests are not known to cause problems when there are many Team folders.

I think this solution is good enough for now and if there are more performance concerns in the future then we can look at it again. As long as the frontend is unusable with many Team folders, it's hard to say if the backend is any problem at all.

[provokateurin]

/backport to stable31