[FEATURE_REQUEST] View books missing a page count

[Skivling]

Is your feature request related to a problem? Please describe.
The statistics page is incomplete and misleading if a few books each year don't have page counts.

Describe the solution you'd like
An option under Books in settings which checks through the database and returns a list of all books without a page count. The list would be filterable as normal. The reader can then go through them and use web searching to find and add the page counts to each book.

Describe alternatives you've considered
Currently I'd have to go through each book one by one to check. With large amounts added (I have 6 years of borrowing history from my library and the past 1.5 years using the app with other books) this is tedious and not worth it.