new: add ``--get-project-name`` option to query project name

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

bin/compose-core

@@ -3683,6 +3683,8 @@ display_help() {
     echo "                              (ignoring any other options)"
     echo "  --dirs                      Display data dirs and quit"
     echo "                              (ignoring any other options)"
+    echo "  --get-project-name          Display project name and quit"
+    echo "                              (ignoring any other options)"
     echo "  -v, --verbose               Be more verbose"
     echo "  -q, --quiet                 Be quiet"
     echo "  -d, --debug                 Print full debugging information (sets also verbose)"
@@ -4016,6 +4018,11 @@ while read-0 arg; do
                     echo "VARDIR: $VARDIR"
                     exit 0
                     ;;
+                --get-project-name)
+                    project=$(get_default_project_name) || return 1
+                    echo "$project"
+                    exit 0
+                    ;;
                 --dry-compose-run)
                     export DRY_COMPOSE_RUN=true
                     ;;