stats-browser: Use libloc instead of our own CSV format for GeoIP

This also makes GeoIP data more precise than our current state, from
`eu` to `eu:de` for Germany, i.e. adding country codes for all countries
and not only for China.

https://git.ipfire.org/?p=location/libloc.git

Current location data can be obtained from
https://location.ipfire.org/databases/1/location.db.xz.

.github/workflows/build.yaml

@@ -29,8 +29,8 @@ jobs:
           override: true
       - uses: Swatinem/rust-cache@v2
       # `demo` crate doesn't work with the MSRV.
-      - name: Exclude `demo` crate from MSRV
-        run: sed -i -e 's/"demo",//' -e 's/"tools",//' Cargo.toml; cargo generate-lockfile
+      - name: Exclude `demo` and `stats-browser` crate from MSRV
+        run: sed -i -e 's/"demo",//' -e 's/"stats-browser",//' -e 's/"tools",//' Cargo.toml; cargo generate-lockfile
         if: ${{ matrix.rust != 'stable' && matrix.rust != 'nightly' }}
       - run: cargo build --locked
       - run: cargo test --locked