Also use this option in the AppImage workflow to make sure to actually
include the intended version of SQLite.
Note this probably only works fine on Unix-like systems.
This downloads and build SQLite from source, currently using version
3.38.5, for building the AppImage file. This way we can include a more
recent version of SQLite instead of shipping the version from Ubuntu
20.04.
See issue #3064.
This improves the existing workflow file for Github Actions by adding
SQLCipher support, fixing the unit tests, and making some other minor
adjustments.
Also a new workfile is added which build and uploads an AppImage. This
workfile skips some of the other build steps like running the tests.