libgimp, app, pdb: Rename GimpVectors to GimpPath

This commit renames the GimpVectors
object to GimpPath in both app/core and
in libgimp. It also renames the files
to gimppath.[ch] and updates the relevant
build and translation files.
There are still outstanding gimp_vectors_* ()
functions on the app side that need to be renamed
in a subsequent commit.

libgimp/gimppath.c

@@ -0,0 +1,71 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-2000 Peter Mattis and Spencer Kimball
+ *
+ * gimppath.c
+ * Copyright (C) Jehan
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "gimp.h"
+
+
+struct _GimpPath
+{
+  GimpItem parent_instance;
+};
+
+G_DEFINE_TYPE (GimpPath, gimp_path, GIMP_TYPE_ITEM)
+
+#define parent_class gimp_path_parent_class
+
+
+static void
+gimp_path_class_init (GimpPathClass *klass)
+{
+}
+
+static void
+gimp_path_init (GimpPath *path)
+{
+}
+
+/**
+ * gimp_path_get_by_id:
+ * @path_id: The path id.
+ *
+ * Returns a #GimpPath representing @path_id. This function
+ * calls gimp_item_get_by_id() and returns the item if it is a path
+ * or %NULL otherwise.
+ *
+ * Returns: (nullable) (transfer none): a #GimpPath for @path_id
+ *          or %NULL if @path_id does not represent a valid
+ *          path. The object belongs to libgimp and you must not
+ *          modify or unref it.
+ *
+ * Since: 3.0
+ **/
+GimpPath *
+gimp_path_get_by_id (gint32 path_id)
+{
+  GimpItem *item = gimp_item_get_by_id (path_id);
+
+  if (GIMP_IS_PATH (item))
+    return (GimpPath *) item;
+
+  return NULL;
+}