Add automated tests for WorldEdit API functions that run under CI

uses a real Minetest instance (Docker)
currently covers most basic manipulations

util/run_tests.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+tempdir=/tmp/mt
+confpath=$tempdir/minetest.conf
+worldpath=$tempdir/world
+
+use_docker=y
+[ -x ../../bin/minetestserver ] && use_docker=
+
+rm -rf $tempdir
+mkdir -p $worldpath
+# the docker image doesn't have devtest
+[ -n "$use_docker" ] || printf '%s\n' gameid=devtest >$worldpath/world.mt
+printf '%s\n' mg_name=singlenode '[end_of_params]' >$worldpath/map_meta.txt
+printf '%s\n' worldedit_run_tests=true max_forceloaded_blocks=9999 >$confpath
+
+if [ -n "$use_docker" ]; then
+	chmod -R 777 $tempdir
+	docker run --rm -i \
+		-v $confpath:/etc/minetest/minetest.conf \
+		-v $tempdir:/var/lib/minetest/.minetest \
+		-v "$PWD/worldedit":/var/lib/minetest/.minetest/world/worldmods/worldedit \
+		registry.gitlab.com/minetest/minetest/server:${MINETEST_VER}
+else
+	mkdir $worldpath/worldmods
+	ln -s "$PWD/worldedit" $worldpath/worldmods/worldedit
+	../../bin/minetestserver --config $confpath --world $worldpath --logfile /dev/null
+fi
+
+test -f $worldpath/tests_ok || exit 1
+exit 0