adapt packaging for Papers

After forking Evince, there have been numerous changes which should be reflected in our packaging:

• DVI backend and synctex support have been dropped
• all libraries and binaries have been renamed and the symbols prefix has been changed from ev_ to pps_
• a significant portion of Papers is written in Rust

This commits renames all packages accordingly, updates library symbols files as well as build dependencies (removing obsolete ones in the process) and adds/changes the necessary bits in debian/rules to build the Rust executable.

A few patches are needed to ensure the packages are built using packaged crates and don't expect a working network connection at build time.