make the information about the total number of objects in the repository available

[ayushin]

If we are to use this package in production we would like to be able to have the information about the total number of pages, i.e. the total number of objects in the repository passed from the backend.

Could you please take a look at the PR and tell what you think?

[ayushin]

OK, so I guess the current PagedListBloc should actually be called InfiniteListBloc and what I need is the actual PagedListBloc that loads just one page at a time.