Rasterise network: filter national sub-network if necessary.

Fix #44
4 jobs for master in 31 minutes and 25 seconds (queued for 1 second)
Name Stage Failure
failed
test-devel Test
R/load_layer.R: 100.00%
R/mapMCDA_datasets.R: 100.00%
R/resolution.R: 100.00%
R/rmext.R: 100.00%
R/wlc.R: 100.00%
>
>
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
test-release Test
Calls: <Anonymous> -> add_hooks -> readLines -> file
In addition: Warning messages:
1: In utils::install.packages(repos = NULL, lib = tmp_lib, pkg$path, :
installation of package ‘/builds/umr-astre/mapMCDA’ had non-zero exit status
2: In file(con, "r") :
cannot open file '/tmp/RtmpqGOmqR/R_LIBS93b151187/mapMCDA/R/mapMCDA': No such file or directory
Execution halted
Uploading artifacts for failed job
ERROR: Job failed: exit code 1