Rename shortest_path to chained_path, which reflects its algorithm more correctly

lib/Slic3r/Fill/Honeycomb.pm

@@ -93,7 +93,7 @@ sub fill_surface {
     )};
     
     return { flow_spacing => $params{flow_spacing} },
-        Slic3r::Polyline::Collection->new(polylines => \@paths)->shortest_path;
+        Slic3r::Polyline::Collection->new(polylines => \@paths)->chained_path;
 }
 
 1;

lib/Slic3r/Fill/Rectilinear.pm

@@ -73,7 +73,7 @@ sub fill_surface {
             }
             : sub { abs($_[X] - $distance_between_lines) <= $tolerance && $_[Y] <= $diagonal_distance };
         
-        foreach my $path ($collection->shortest_path) {
+        foreach my $path ($collection->chained_path) {
             if (@paths) {
                 my @distance = map abs($path->[0][$_] - $paths[-1][-1][$_]), (X,Y);