GitLab

This compiles and links NSS/application-services with lto, and also adds a check
which will make the building of the application-services project fail if it finds
networking symbols in the final built libraries.

We remove the Fenix targets that were due to Fennec-based builds still
being around. Additionally, we move the *fenix* projects to their
non-Fenix counterparts in case they only existed due to Fennec-based
builds. Thirdly, we do a firefox project clean-up as all the mobile bits
moved to the geckoview project.