Add grid_map_geo source entry to humble distro

[Ryanf55]

Please Add This Package to be indexed in the rosdistro.

Package name: grid_map_geo

grid_map_geo is a library for loading elevation maps and color data into a grid_map object.

The source is here:
https://github.com/ethz-asl/grid_map_geo

The ros2-gpb release team is here:
ros2-gbp/ros2-gbp-github-org#471 (comment)

Checks

• All packages have a declared license in the package.xml
• This repository has a LICENSE file
• This package is expected to build on the submitted rosdistro

[clalancette]

New package review checklist

• At least one of the following must be present
  • Top level license file:
  • Per package license files:
• License is OSI-approved:
• License correctly listed in package.xmls
• Public source repo: https://github.com/ethz-asl/grid_map_geo
• Source repository contains ROS packages
• Each package meets REP-144 naming conventions