Re-sort title-sorted bookshelf after title change

[mikiher]

Brief summary

When a bookshelf is sorted by title and the title of a book/podcast changes (e.g. after being edited), the bookshelf is rebuilt so the book appears at its proper position (based on its new title)

Which issue is fixed?

Fixes #3998

In-depth Description

Up until now, when LazyBookshelf got an item_updated message from the server, it only replaced the old entity with the updated entity. With this change, if the current sort order is by title, and a change of title is detected, resetEntities() is called, and the item is moved to its new position.

How have you tested this?

Changed title of books/podcasts and verified that after saving the change, the book/podcast moved to its new position.

[advplyr]

I made a small update so that the scroll position is kept for title change re-sorts. I figured because we know the page size will be the same on an update we might as well keep the scroll pos.

Thanks!