Add fuse2 dependency, fix dynamic SQLite loading

Kind of killing two birds in one stone. :)

Fossil has a fusefs command where a repository is mounted so that you can browse commits and tags without having to open a check-out for each one.

Additionally, the PKGBUILD seemed to intend to disable the vendored SQLite but it wasn't working. I changed out --disable-internal-sqlite for --with-sqlite=/usr and that did the trick. And even as it's unlikely for an Arch system to have an outdated SQLite, I still added a version check (>=3.46.0) on the sqlite dependency. ./configure --print-minimum-sqlite-version can be used in the future to take note of new requirements.