feat(slam): implement semantic mapping and landmark database

Author: 10xdev4u-alt

navpath_ws/src/navpath_slam/src/semantic_mapping.py

@@ -0,0 +1,7 @@
+import rclpy
+from rclpy.node import Node
+
+class SemanticMapping(Node):
+    def __init__(self):
+        super().__init__('semantic_mapping')
+        # Object-level SLAM landmarks